ir 



Brake 
Catechism 



BY 



aQ 4 fa^inMfrcr* 



Twenty Fourth Edition 





Class. 
Book. 






9 



Showing ,l DE 
EYE LOCOM 
TOR with"BEl 
DER LUBRIC 
Feed, and Wes 



Copyright^ . 



COPYRIGHT DEPOSIT: 




) 



"DETROIT" 

SIGHT -FEED 

AIR CYLINDER 

LUBRICATOR 

Insures the proper lubrication of the 
Air Cylinder of Locomotive Air Brake 
Pump. Provides complete and conven- 
ient control of Air Cylinder Lubrica- 
tion from Engine Cab. Guarantees the 
application of just the right quantity of oil at the right time. It's 
simple — consists of 3 features — the Emergency Valve "H" Sight 
Feed Fitting "K" Check Valve Connection "S." Approved and highly 
recommended by leading Railway Mechanical Experts. Send for 
our Locomotive Lubricator and Air Cylinder Catalog* and 
Instruction Book "R," it's free. 

D etroit L ubricator P om pan y , 

DETROIT, U. S. A. 



Double Feed Type 



THE 

Air Brake Catechism 

AND 

Instruction Book 

On tho Construction and 
Operation off 

THE WESTINGHOUSE 

AND 

THE NEW YORK 

AIR BRAKES 

With a List of 

Examination Questions for Enginemen 

and Trainmen 

By 



Copyright by C. B. Conger, Grand Rapids, Mich. 
1910. 



Twenty Fourth Edition 



*° 



<*v 



PREFACE 

24th Edition 

In this enlarged edition of the Air Brake Catechism 
considerable new matter has been added which will prove 
of interest not only to those who are learning about the 
operation of the brake equipment from their own observa- 
tion and experience, but to those who have the advantage 
of an instruction car with a regular instructor. This 
subject of self-instruction in all its details is so large that 
only a small part of it can be taken up in this little book, 
but the principal points are brought to notice. 

The work done by the air brake operator in handling 
trains is becoming more skillful every year; he who 
wishes to keep up with the best practice must continually 
try to improve his work. This can only be done by learn- 
ing and practicing the best methods. Bear in mind that 
good judgment is the first requisite for a successful air 
brakeman, the addition of knowledge of the construction 
so as to locate defects and their remedies, and correct 
methods of handling, to good' judgment, will make a 
skillful man under all conditions. 

At the present day every one connected with the work- 
ing of the air brake is expected to pass regular examina- 
tions, and these examinations are getting more strict each 
year. The list of examination questions will call atten- 
tion to points in the construction and handling of the 
brake which you should know 'if; you wish to pass. 

The construction and operalfon of the air pump, brake 
valve and triple valve, as far as it interests enginemen, is 
explained, the matter of repairs is not taken up. 

All the new designs of locomotive and high duty car 
brakes of both Air Brake companies that are in general 
service at this date are explained in this Catechism. 



OttA8-59276 AAt\M\ 



INTRODUCTION 

At the present day so much depends on the proper 
handling of the Automatic Brake that a definite knowledge 
is required from all men in train service of its operation 
when in good order, and how to locate defects or break- 
downs, as well as how to avoid the difficulties arising from 
them. 

This applies to the veteran as well as to the beginner. 
The changes in the mechanism, caused by the new and 
improved devices brought into service to take care of 
longer freight trains and faster passenger trains, as well 
as the devices for independent operation of the locomotive 
brake, call for study on the part of the men who have 
handled the brake for years, for a passenger train of 
moderate length equipped with ordinary triple valves 
and a long train with all high speed brakes are two 
widely different propositions, and the veteran looks for 
information on them. As for the beginner, he can not 
learn it all from experience, as no one is allowed to 
handle important trains until he has shown, either by an 
examination or by handling a moving train under the 
supervision of some man who can judge, that he has 
the necessary knowledge to properly operate the brake 
under all ordinary conditions. 

This has brought about a demand for a clear and prac- 
tical form of instruction in air brake practice, not so much 
to instruct the beginner on all the points as to put him in 
the way of learning them himself; and this introductory 
chapter is intended to help those who set out to learn the 
theory and have a chance to operate the brake or see it 
operated. This can best be done by learning the foun- 
dation principles first, studying the action of the important 
primary parts of the machine; the secondary parts will 
then work their way in so you understand the whole 
properly. Much time may be wasted by beginning at the 



4 SELF INSTRUCTION 

wrong end to unravel air brake operations. If you are 
too hasty and jump at conclusions, you may be wrong; 
better not know anything about it than know it wrong. 
Therefore, take time enough at first to learn it right; 
you will never regret it. 

There is nothing mysterious about the operation of the 
air brake. Each part has its own duty to perform. Take 
each part by itself and study it up, then get an idea of its 
relation to the other parts, and you will find out that it is 
easy. You cannot learn it all at once, or by once reading 
over an instruction book. In studying the construction 
and principle on which it operates, it is an advantage to 
have help from some one who can instruct you. When 
you come to operate it, the machinery in actual operation 
Is the best instructor. 

When you see the air brake working every day, some- 
limes making -a good stop, at others not controlling the 
train as you think it should, the operation may seem 
mysterious, but it is governed by fixed laws of mechanics 
and forces. If you take pains to learn these laws and 
about the forces, and examine each part of the mechanism, 
it will be clear to you. 

Attention is called to explanations of some of these 
operations in the succeeding pages of the Air Brake Cate- 
chism. Many of these operations are explained in more 
than one manner in connection with the movements of 
•other parts of the apparatus. 

In the first place, all the parts of the brake which are 
named in question 1 of the Catechism, are charged with 
compressed air, which comes from the air pump to the 
•main reservoir, then through the ports in the brake valve 
Into the brake pipe and triple valve, from there it passes 
through the feed port in the triple valve into the auxiliary 
reservoir provided for each complete brake. When the 
"brake is ready to operate, the pressure is equal in the 
brake pipe, in the triple valve on both sides of the triple 
piston, and in the auxiliary reservoir. When you change 
the relation of these pressures in different parts of the 



PLAIN TRIPLE VALVE 5 

equipment, the effort the compressed air makes to equalize, 
by the high pressure air pushing against the low pressure 
air, moves the different parts of the air brake that can be 
moved in this manner away from the high pressures. 

When it is once fixed in your mind what pressure you 
have in each place, and that any change of pressure will 
cause the movable parts of the valves to change their 
positions, closing some of the openings through which the 
air can pass and opening others, it is plain that the next 
step is to find out just what openings the air must pass 
through at each operation, whether applying or releasing 
the brake, always remembering that the high pressure air 
tries to flow into a space of lower pressure. 

When studying the equalizing processes in the operation 
of compressed air equipment, remember that it is air that 
flows from one part of the equipment to another and not 
pressure. Pressure is only a condition, air is a substance 
or material. A substance can flow from one cavity or 
receptacle to another, but a condition can not flow through 
an opening. When compressed air flows from any part of 
the equipment to another, as from the auxiliary to the 
brake cylinder, it will change the conditions or pressure 
in these places, but the pressure does not flow either way. 

It will take away much of the mystery of equalization 
if you will bear these facts in mind. 

We will take up the plain triple valve first, as the 
process of equalization is best explained with it. Yon 
will notice in the cut on next page of the plain triple valve 
in the position for charging the auxiliary reservoir and 
exhausting the air from brake cylinder, that the triple 
piston 5 is the dividing line when the pressures are 
unequal; that the brake pipe pressure is against the lower 
side of this piston and auxiliary pressure on top. There is 
a small passage cut in the side of the cylinder around the 
piston, called a feed port, at m, through which air can 
pass from the brake pipe around the piston 5, and up 
beside the slide valve 6 into the auxiliary at Y, when triple 
piston is clear up in release position; this is the opening 



PLAIN TRIPLE VALVE 



through which air can equalize in brake pipe and auxiliary. 
The piston acts as a valve to open and close this feed port. 
This port m is very small, and equalization takes place 
slowly through it. A brief explanation of the reasons for 
its small size is found farther along in the book. 

As the auxiliary stores the compressed air used for 
applying its own brake, it must first be charged with a full 



i PiPE TAP 




OF.TAILS 

Triple-Valve Body 
Cylinder Cap. 
Cap Nut. 
Piston 
Slide Valve. 
Graduating Valve. 
Graduating Stem. 
Graduating Spring. 
Graduating-Stem Nut. 
Cylinder Gasket. 
Packing Ring. 
Bolt and Nut. 
Slide- Valve Spring. 



RELEASE AND EXHAUST POSITION. 

supply of air; which will raise its pressure to the stand- 
ard — usually 70 pounds — and it takes about a minute and 
10 seconds for air enough to flow around the piston to 
equalize the pressure at 70 pounds. To apply the brake 
with a triple valve the brake pipe pressure must be re- 
duced. As soon as any reduction of pressure is made in 
the brake pipe the auxiliary pressure will be greater and 



SERVICE APPLICATION 7 

force the triple piston down, following the decrease of 
pressure in brake pipe end of triple. 

This first movement of the piston does not set the 
brake. There is some slack between the collar on the 
piston rod and the top of slide valve 6 — about five thirty- 
seconds of an inch — a very slight reduction of pressure 
under the piston moves it down the amount of this slack, 




SERVICE APPLICATION. 



LAP POSITION. 



closing feed port m and pulling graduating valve 7 off its 
seat in slide valve. As the slide valve has the auxiliary 
pressure holding it on its seat, more change of pressure 
under the piston is needed to move the slide valve — a 
point to remember when you move the triple valve to 
release position. When the piston comes down, bringing 
with it the slide valve, a port z, leading from the seat 
of graduating valve 7, is opened to f, allowing the 



8 SERVICE APPLICATION 

auxiliary air to pass from the graduating valve into the 
brake cylinder. This also has a movable piston that 
pushes against levers which are so coupled up that the 
brake shoes are forced against the wheels. The operation 
of this triple piston with a moderate reduction of brake 
pipe pressure, say from 70 pounds down to 63, will show 
the exactness of this equalization principle. 

When the triple piston 5 comes down, following a 
reduction of 7 pounds in the brake pipe (and the piston 
does not wait till the entire reduction of 7 pounds is 
made), and slide valve 6 and graduating valve 7 opens, 
the air in the auxiliary at 70 pounds begins to expand 
into the brake cylinder, as shown in cut of service appli- 
cation. As soon as enough air has gone into the cylinder 
to reduce the auxiliary pressure a little below 63 pounds, 
the brake pipe pressure is then greatest; hence triple 
piston moves up, also moving the graduating valve 7 
and closing it. This cuts off the flow of air into the 
brake cylinder. As only a part of the full supply of air 
has passed into the brake cylinder, it sets the brake with 
a partial application and holds it set, for the piston does 
not move the slide valve 6 up and open the exhaust port 
k to air port f, as shown in cut of release position. For 
a more detailed statement of the operation of the graduat- 
ing valve, see the answer to a question farther along in 
this book. Thus you see the triple piston moves between 
the brake pipe and auxiliary pressures, always towards 
the lesser one. 

A graduating stem 8 and its spring o, in the bottom 
case of the triple, serve to stop the piston at a point in its 
travel where port z will be exactly opposite port f. This 
stem and spring are not moved in a partial service appli- 
cation, because when these ports are wide open the air 
will pass from the auxiliary to the cylinder as fast as it is 
going out of the brake pipe, this will reduce the auxiliary 
pressure as fast as the brake pipe pressure reduces. 

If the relations between the pressures on either side of 
triple piston are changed, it will move toward the lower 



RELEASING BRAKES 



9 



pressure until the limit of its travel is reached, or until 
the relation between the pressures is changed the other 
way; this will stop its movement if pressures are equal- 
ized, or move it the other way if pressure is increased. 
Increasing the pressure in brake pipe side of triple over 
the auxiliary moves the triple piston clear up, moves the 
slide valve 6, opens exhaust port k to air port f, allows 




The plain triple valve 
moves to this position 
when the train pipe pres- 
sure is lower than the 
equalizing pressure of the 
cylinder and auxiliary 
either with a quick or a 
slow reduction. 



EMERGENCY APPLICATION. 

the air to escape from brake cylinder and releases the 
brake; so you see, charging up the brake pipe to standard 
pressure releases the brake. As the feed port m is also 
opened when the piston 5 is clear up, the air flows into 
auxiliary, equalizing its pressure with the brake pipe. To 
change the relations between the pressures in any other 
way is done by letting out some of the air— the train man 



10 EMERGENCY APPLICATION 

releases the brake by bleeding out the auxiliary pressure 
until it is lower than brake pipe pressure. 

If a reduction of the brake pipe pressure of more than 
20 pounds is made, as from 70 to below 50, the auxiliary 
pressure must also be reduced 20 pounds or more before it 
will allow the piston 5 to move up and close the graduating 
valve. 

The brake cylinder is of such a size — if it has the 
proper piston travel — in proportion to the auxiliary reser- 
voir that if air is allowed to flow from the auxiliary into 
the cylinder it will equalize in both of them at about 
five-sevenths of the original pressure, which is 50 pounds 
in case of 70 pounds originally. After this equalization 
has taken place no more reduction of pressure will be 
made in the reservoir, except by a leak or at the bleeder 
and the triple piston will move clear down to the position, 
which with a gradual service application is called full 
application position. This is the same as the emergency 
application position. You will notice the slide valve has 
uncovered the air port f so air can pass through freely 
and hold the brake cylinder pressure equal to the auxiliary 
pressure. The stud or post on the bottom of triple piston 
has pushed the graduating stem 8 down, compressing its 
spring o. This spring helps to stop the piston 5 at the 
proper place with a partial service application and assists 
in starting the piston up to release after a full application. 

After thoroughly posting yourself on the way in which 
the plain triple operates by the reduction or equalization 
of pressures, you can then take up the engine equipment. 
It is a good plan to know just how the pump operates, its 
care and management, but that can be left till later; it is 
treated of farther along in this book. The pump generally 
goes ahead with its work from beginning to end of the 
trip without much attention from the engineer; the rest 
of the equipment depends on the skill and knowledge of 
the engineer for its successful operation, as it responds 
directly to his manipulation. 

The brake valve controls the passage of air between the 



THE BRAKE VALVE 11 

main reservoir and brake pipe or brake pipe and the 
atmosphere. 

The main reservoir air pressure is always in the top of 
the valve holding the rotary valve 13 on its seat; the 
brake pipe air is under the equalizing piston 17 at all times. 
The air over the piston can be called brake-valve air. 
Brake valve and brake pipe air can equalize when the 
rotary is on running position, and in full release. This is 
further explained in detail later on. The equalizing 
piston 17 is moved up, opening the discharge or brake 
pipe exhaust port n, or down, closing the port, by a change 
of pressure on either side, just the same as the triple 
piston. The presures are changed by opening or closing 
the various ports in the valve. Opening preliminary 
exhaust port h reduces the pressure over piston 17 so that 
brake pipe pressure raises the piston; brake pipe pressure 
reducing through port n brings piston down. The rotary 
13 is moved by the engineer, its office is to put in com- 
munication the various openings or ports that will let 
the air pass through. Locate these ports, next find out 
just what they are for and in what positions of the rotary 
they are open and shut. The best way to do this, if you 
have no sectional valve to study on, is to get a complete 
valve for a few hours and dissect it, using a piece of fine 
copper wire to run through the ports, which will show 
the course of the air; this wire can be bent in any direc- 
tion and its use is not likely to scratch the seats or valve. 
After locating all the ports through which main reservoir 
air can flow into brake pipe or the chamber D over piston 
17, then see in what position of the rotary all ports are 
covered, and figure out which ports are covered first and 
why it is necessary to stop the flow of air through them. 

You will probably notice that before any ports are 
opened to allow air to escape from the brake pipe the main 
reservoir air is cut off from the brake pipe, so it can not 
supply the brake pipe while you are reducing that. Other- 
wise the triple valve would not feel any reduction of pres- 
sure and brake would not be set. Then when you come to 



THE BRAKE VALVE 13 

' locate the ports that are opened to reduce the brake pipe 
pressure and actuate the triple, it will be necessary to 
know just exactly the principle of operation of the equal- 
izing discharge valve. 

On a long train the reduction of brake pipe pressure 
must be the same at each triple if we expect each brake 
to be set at the same time and with the same relative 
power. To make this reduction of pressure alike for all 
the triples, or what is the same, for all the cars in the 
train, we must allow the air to escape from the brake 
pipe gradually so the reduction will not be any more 
violent from the first car than from the last one, nor 
should the escape of air be closed till the same reduction 
has been made in each car. The discharge should not be 
stopped suddenly before the pressure in the last cars has 
equalized with the first ones, or the momentum of air 
flowing from rear cars, as well as equalizing pressures in 
all cars, will raise the brake pipe pressure in the cars 
nearest the brake valve and tend to release their brakes. 
This gradual closing of the brake pipe exhaust, the brake 
valve is intended to do automatically. Its principle of 
operation is, the engineer makes the proper reduction of 
pressure in the brake valve over the equalizing piston 17, 
and the action of the piston 17 reduces the brake pipe 
pressure to an equal amount in all the cars, whether few 
or many. 

Before you move the rotary far enough to open the 
preliminary exhaust port h, the equalizing port g, which 
allows brake pipe air to pass from brake pipe to chamber 
D, over piston //, is closed ; this cuts off chamber D from 
any other pressure ; you can then make a reduction on top 
of piston 17, so brake pipe pressure will raise it up and 
hold discharge n open till the pressure below is a little 
less than it is above, when piston is moved down by the 
chamber D pressure, closing brake pipe discharge. 

With the equalizing discharge valve, the black hand 
of the double gage is connected with chamber D at all 
times ; if the rotary is in either full release or running 



14 THE BRAKE VALVE 

position the equalizing port g connects it to the brake pipe 
air so it shows that pressure also. When the brake is set 
with a service application, the pressures equalize so nearly 
on each side of piston at the instant brake pipe exhaust 
closes that the black hand is expected to show brake pipe 
pressure then also. In the emergency position the black 
hand does not at once show the amount of the reduction. 
You will find this further explained later. 

If the packing ring in piston if leaks very much, the 
black hand will show brake pipe pressure when rotary is 
on lap, as the air pressures can equalize past this leaky 
packing ring; all of them leak a little. There is a leather 
gasket above this piston to prevent leakage during a serv- 
ice application, but not when the piston is in normal 
position. Look out for this defect when operating the 
brake. The brake valve reservoir is connected with the 
valve for the purpose of giving a larger volume of air to 
chamber D in order to insure a gradual reduction of 
pressure there. 

Up to this point we will assume that the student has 
followed the action of the brake in a service or graduated 
application. There is what we call the emergency or quick 
action, produced by a different set of operations peculiar 
to the quick action triple valve only. We will, go to the 
beginning and inquire why this action is necessary. 

On a long train of air braked cars, to avoid a severe 
shock to the rear part of train when brakes are applied 
from the head end of train very suddenly, as by bursting 
a hose or breaking apart of the train, or in case of danger 
when it is necessary to set the brake from the engine very 
hard so as to stop as quickly as possible, the brakes should 
set on the rear cars quicky enough so the slack will not 
run up against head cars and damage cars or draft gear. 
Then, in case of danger, every second after the brake is 
applied at the engine before it begins to set on last cars 
and hold them, the train is getting nearer the danger; so 
a brake that can be set instantly on the whole train will 
stop the train quicker than one which sets slowly from car 



THE TRIPLE VALVE 



15- 



to car. With the plain triples the air in brake pipe will be 
exhausted at one place only, either where an opening is 
made in brake pipe or at brake valve ; this takes several 
seconds to affect the farthest car. If an opening can be 
made to exhaust this air at each car and reduce the brake 
pipe pressure, the action of the brakes on a long train can 
be made nearly simultaneous, so nearly so that the brakes 
are all set before the slack can run out. The quick action 




DBTAILS. 

2 Triple valve body. 

3 Slide valve. 

4 Piston. 

6 Slide-valve spring. 

7 Graduating valve. 



A 

'JO TRAIN PIPE 



8 Emergency-valve piston, 

9 Emergency-valve seat. 

10 Emergency valve. 

11 Rubber seat. 

12 Check-valve spring. 

13 Check-valve case. 
15 Check valve. 

21 Graduating stem. 

22 Graduating spring. 



QUICK -ACTION TRIPLE VAI<VE — RELEASE POSITION. 

triple is designed to exhaust a portion of the brake pipe air 



16 QUICK ACTION TRIPLE VALVE 

at each triple, so as to set the next brake suddenly. To 
thoroughly understand how the quick action triple can 
exhaust some of the air from the brake pipe suddenly and 
reduce the pressure so as to affect the next triple in the 
same manner, it will be necessary to study the construction 
of the quick action valve. This triple has the same open- 
ings to admit air from the brake pipe to the auxiliary that 
we find in the plain triple. In the quick action triple they 
are shown at e through g and feed port i. But there is 
another channel for air to pass from the brake pipe into 
the brake cylinder in this valve, which is from the check 
valve case 13 into y, then into x and into brake cylinder at 
C. These openings are ordinarily kept closed to the pass- 
age of the air in either direction; the rubber seated emer- 
gency valve 10 keeps the brake pipe air from getting into 
the cylinder, and the check valve 15 keeps the air in brake 
cylinder from getting back into brake pipe. These two 
valves are held on their seats by a spring, shown at 12, as 
well as by the air pressures. Now it follows that, if you 
wish this triple to make an opening to let the air out of 
brake pipe suddenly, this valve 10 must be moved away 
from its seat against the brake pipe pressure and the strain 
of the spring 12. For this purpose piston 8 is used. A 
port t, which is shown just over the figure 8, can be 
opened by the slide valve 3, letting the air from the auxil- 
iary on top of piston 8; with auxiliary reservoir pressure 
over this piston and no pressure at all or a very low one 
below it, piston 8 goes down instantly, forcing valve 10 
away from its seat. The brake pipe air then moves check 
15 up and flows through C into brake cylinder till press- 
ures equalize. 

When these valves 10 and 15 are opened in this manner, 
the brake pipe air goes past them like a flash through the 
large ports into the empty brake cylinder, setting the 
brake with the pressure at which the brake pipe and brake 
cylinder can equalize, which is somewhere near 20 pounds. 
At the same time port s, in the end of slide valve 3, is 
open, air from auxiliary flows through r and piles in on 



QUICK ACTION TRIPLE VALVE 17 

top of brake pipe air in cylinder, raising the cylinder press- 
ure at full equalization to 60 pounds. The brake pipe air 
equalizes first with cylinder, through large ports, and 
auxiliary pressure last, through small ports. Considerable 
air passes around piston 8, which is not an air tight fit 
in its bushing. 

Now for the means employed to let auxiliary reservoir 
pressure on top of piston 8 at one time to produce "quick 
action" and keep it out at another to preserve the grad- 
uated application. As long as this triple is used with a 
graduated application, slide valve 3 does not move ovefr 
far enough to uncover emergency port t, as with a gradual 
reduction of brake pipe pressure auxiliary presure will 
be reduced equally with brake pipe pressure through the 
graduating valve 7 and its port 2. The graduating stem 
21 and its spring 22 ordinarily stop the movement of the 
piston 4 when it reaches the service application position. 
But if brake pipe pressure is reduced so suddenly and to 
such an amount that the graduating valve can not reduce 
auxiliary pressure equally with brake pipe reduction, and 
graduating spring does not stop the piston, the greater 
auxiliary pressure will move piston 4 and slide valve 3 
far enough so port t will be uncovered, auxiliary air will 
move piston 8, valves 10 and 15 will move at once and 
"quick action" is the result. The Westinghouse Co. have 
made a quick service triple valve that allows a small 
quantity of brake pipe air to flow into the brake cylinder 
during a service application and another type that uses 
air from a supplementary reservoir. These will be de- 
scribed later on in this book. 

A sticky triple valve or any defect in valve 7 that will 
prevent air getting past it will cause quick action opera- 
tion with a moderate service application if you have a 
short train. The equalization of pressures is the founda- 
tion principle to look for in the operation of the quick 
action triple. 

It is necessary to restrict the flow of air through some 
of the openings in triples and brake valve in order to be 



18 EQUALIZATION 

sure to handle a long train with safety. This refers more 
particularly to the "feed ports" in the triples for recharg- 
ing auxiliaries, the "preliminary exhaust port" h, train 
pipe exhaust n and exhaust ports in triple valves. The 
proper size of these ports has been determined by the 
experience of many years. 

Perhaps it would be well to study on the matter of 
equalization of different pressures of air in the equipment, 
as if this is well understood you can solve other problems 
in air brake operations more easily. It is the law that 
where compressed air in a certain sized vessel expands into 
an empty one, the pressure is reduced in the full one in 
proportion to the increased volume the air has to occupy. 
From this you can see that in the case of the brake cylin- 
der and auxiliary the auxiliary pressure will be reduced 
more if the brake cylinder is large in proportion to the 
auxiliary than if it is small. Apply this law to the cylin- 
ders having different piston travels; a cylinder having a 
long piston travel holds a greater volume of air than the 
one with short travel, so we can expect the one with long 
travel to reduce the auxiliary pressure to a lower point 
than the short travel, and it is found that a travel of 11 
inches of the freight brake piston gives a final equalized 
pressure of close to 45 pounds, while a short travel of 8 
inches, which is between 4 and 11 inches, will give a final 
equalization of about 50 pounds. The difference of press- 
ures with long and short piston travels is more marked 
with partial applications than with full equalization . A 
5 pound reduction of auxiliary pressure will give about 18 
pounds per inch on a piston with 4 inches travel; while 
with the 11-inch travel piston, the pressure will not show 
anything. This will give different brake powers on dif- 
ferent cars in the train, although it should be equally 
proportioned to the weights of the cars ; unequal brake 
power makes some cars hold less than others, so the strain 
is not equally distributed throughout the train, a point 
in equalization worth studying on. 

The final point at which auxiliaries and their cylinders 



EQUALIZATION 19 

equalize cuts quite a figure in operating the triples to 
release the brakes. A variation in piston travel of the 
different brakes changes this point of final equalization 
and will be explained later. As was stated in explaining 
the operation of the triple piston, the brake pipe pressure 
must be greater than the auxiliary pressure to move the 
triple piston up so slide valve will open exhaust port and 
let air in brake cylinder equalize with the atmosphere; 
then the brake piston will have no air pressure on either 
side of it. This relieves the strain on brake levers and 
shoes. 

If auxiliary pressures on this final equalization are 
unequal and brake pipe pressure is not raised at once 
higher than the highest auxiliary pressure, all the brakes 
will not release at once. This leads us to consider the 
question of equalization of the train pipe and main reser- 
voir pressures when you desire to release the brakes. 

If the brake pipe is long it will take more air from main 
reservoir to equalize at a certain stated pressure than if it 
is short, for a long brake pipe holds more air than a short 
one. Then, again, if the brake pipe has considerable com- 
pressed air left in it after setting the brake, it will equalize 
at a higher point than if it is empty. This emphasizes the 
fact that it will be hard work to release the brakes on a 
long train if you exhaust all the air in making an ap- 
plication. 

Another place where equalization is important is on the 
second application shortly after releasing brakes. It takes 
time for the brake pipe and auxiliary pressures to equalize. 
If you do not wait this proper time the auxiliary will not 
have charged to standard pressure, and, of course, when 
brake is set it will not reach as high a final pressure on 
brake piston, which reduces the braking power. 

Equalization between brake pipe and auxiliary on 
making the reduction for a second application is very 
important, because if brake pipe has a high pressure which 
the auxiliary has not reached, the triple piston cannot 
move till the brake pipe pressure has been drawn down a 



20 BRAKE OPERATION 

trifle lower than the auxiliary. If one is 80 and the other 
60; it means a reduction of 20 pounds before brake begins 
to set, and about 20 more to set all brakes tight. This 
affects the work of the brake on a short train more than 
a long one. With a large main reservoir and a short train 
it is easily done. 

This defective handling of the brake is called "over- 
charging the brake pipe," and can be avoided by returning 
the brake valve to lap from full release as soon as the 
brake pipe has had time to charge up its whole length, 
which will move all triples to exhaust position and quickly 
equalize the brake pipe and auxiliary pressures. When 
these pressures are equalized, a very slight reduction in 
the brake pipe pressure sets all the triples to work at once. 
In stopping a short passenger train for baggage or at a 
water plug, if the stop is being made too soon, go to a full 
release for an instant to move all the triples to release, 
then back to service application, making a service reduc- 
tion of 6 or 8 pounds which will probably set the triples 
before all the air has passed out of brake cylinders, and 
in addition to holding the brake set at a low pressure will 
have all of them ready for a further application at an 
instant's notice so that you can stop at the exact spot 
required. Never try this with a long train of any kind at 
slow- speed, as you are liable to break the train in two. 

A few hints on getting ready to make a good stop and 
knowing whether you can depend on the brake to operate 
properly may be of service here. 

When operating the brake valve, you should listen to 
the sound of the brake pipe air discharging from it, 
because the sound tells how many cars you have in your 
train with brake pipe connected and how the valve is 
doing its work, just as the exhaust of the locomotive tells 
whether the valve motion is in order ; any unusual sound 
notifies you that something is wrong. 

When you make a test of the train brake before start- 
ing out, make the same kind of an application as when 
stopping at a station, by successive reductions; a 5 to 7 



BRAKE OPERATION 21 

pound reduction for the first one, lighter ones afterwards; 
then you will know how -the brake will work when making 
station stops. It should be full application to get the full 
piston travel. 

Never make an emergency application when testing 
brakes unless specially called for, and then not till after 
the first test has been finished. 

If the brake leverage on the train is adjusted for 70 
pounds train pressure, it is not safe to carry either more or 
less. If you carry less, you cannot stop quickly when you 
have to; if you carry more and skid the wheels, you will 
slide by and will spoil a lot of wheels. We will speak of 
this matter of leverage later on in connection with the 
High Speed Brake and L Triple. 

Have your air gage properly placed and well lighted, 
so that it can be seen without taking your eyes too far off 
the track and signals. Consult it often till you learn the 
air brake business. If it does not register correctly or 
sticks when the pressure is changing, call the attention of 
the proper party to it. 

It pays to inspect and test your engine equipment care- 
fully before leaving the engine house; it may save you a 
failure on the road. 

Drain the main reservoir daily; the distributing valve 
and the tender triple should be drained regularly in cold 
weather. It is a good plan to open the cocks at rear of 
tender and blow out the train pipes for both brake and 
signal line before coupling to the train. 

Too much oil used in the air end of the pump does 
more harm than not enough, as it chokes up all the small 
openings in the engine equipment. The piston rod pack- 
ing needs more oil than the air piston; the air valves do 
not need any. Use good valve oil always. 



WHEN OPERATING THE AUTOMATIC BRAKE 
REMEMBER 

That the compressed air stored in the main reservoir is 



22 BRAKE OPERATIONS 

used to charge up the brake pipe and auxiliary reservoirs, 
and that it is used to release the .brake. Do not have any 
water in any reservoir, as it takes up the room needed 
for air. 

That the compressed air stored in auxiliary reservoir 
is used to set the brake. There is an independent supply 
for each brake. Keep a full supply in each auxiliary. 

That the brake is set by any reduction of pressure in 
the brake pipe, no matter how it is made, if it is sufficient 
to move the triple piston and valve. 

That the brake pipe pressure must be reduced 5 to 7 
pounds at first application, or brake pistons will not travel 
over leakage grooves, allowing brake to leak off. 

That the brake pipe pressure must be raised above the 
auxiliary pressure, or the auxiliary pressure reduced by 
bleeding, before the brake will release. 

That you cannot recharge an auxiliary reservoir until 
the exhaust port in triple is wide open, unless air leaks 
past triple piston, as the feed port does not open until 
after the exhaust port is open. 

That a second application after release does not set the 
brake as tight as the first full application, unless the 
auxiliaries have had time to recharge to standard pressure. 
This takes from 25 to 45 seconds. 

That the small reservoir attached to brake valve is put 
there to give a larger supply of air for the preliminary 
exhaust of brake valve so you can make a gradual re- 
duction. 

That if your driver brake does not work quickly and 
hold well with service application, in ninety-nine times out 
of a hundred it is on account of a leak. 

That the distributing valve used with the locomotive 
brake must be kept clean and all pipe joints tight if you 
expect to get good service from it. 

That the position of the straight air brake valve and 
the independent brake valve has all to do with the applica- 
tion and release by the automatic brake valve of the 
locomotive brake. 



DEFINITIONS 23 

That in all these questions and answers it is under- 
stood unless otherwise stated, that 70 pounds is the stand- 
ard brake pipe and auxiliary pressure; 90 pounds main 
reservoir pressure; and 8 inches the standard piston travel 
for all passenger, freight and tender brake pistons. The 
brake piston travels an inch or more farther when train is 
running than with a standing test, so travel should be 
adjusted to less than 8 inches. 

And lastly, we will, define some of the terms which are 
used to shorten the explanations you may hear. 

A partial application means that the brake is set with 
part of its full force; the brake cylinder pressure has not 
equalized with the auxiliary reservoir pressure. 

A full application means that the brake cylinder press- 
ure has equalized with the auxiliary pressure, and has, 
therefore, got the full pressure that can be obtained from 
the air stored in the auxiliary. Be sure to distinguish 
between a reduction and an application when telling any 
one how the brake worked. A reduction is allowing air 
to pass out of the train pipe whether the brake sets full 
or partially. No matter how many reductions of brake 
pipe pressure you make, it is only one application till it is 
released. You can reduce the brake pipe pressure a few 
pounds at a time and make eight or ten successive reduc- 
tions, but it is only one application if it has not been 
released. ' 

A graduated or service application means a gradual 
reduction of brake pipe pressure which sets the brake 
slowly. In a graduated application it is not expected that 
the quick action parts of any triple valve will operate. 

An emergency application means a sudden and heavy 
enough reduction of brake pipe pressure to set the brake 
with full force at the first movement of the triple valve. 
With this application the quick action part of the triple 
valve operates, so that air from the brake pipe passes into 
the brake cylinder and equalizes, after which the auxiliary 
and cylinder pressures also equalize. 



THE 8 INCH AIR PUMP 

The sectional view of this pump shows the steam and 
air pistons 10 and 11 and all the steam valves in their 
positions when the steam piston is making its stroke 
upward. 

The live steam comes from the boiler through the 
governor and passage m into the chamber between the 
heads of the main steam valve /. It also goes into port h 
and through a passage in the wall of the steam cylinder 
and in the top head, which is not shown as this port is 
in the section cut away. This passage from h leads live 
steam constantly into the steam chest e of the reversing 
valve 16; it can pass through port a into the cylinder 
and over the reversing piston 23, pushing it down; for 
the combined area of the piston 23 and the small one 7 
is greater that that of the top one 7. This opens the 
steam port in the bushing 26; steam then passes under 
steam piston 10. 

At the same time the exhaust ports in bushing 25 are 
open so any steam in the top end of the cylinder escapes 
at y through f and g to the exhaust pipe. This moves the 
steam piston up, bringing up the air piston 11. As the air 
piston moves up, any air above it escapes through port p 
by raising discharge valve 30 and passes into the main 
reservoir. At the same time the lower end of the air 
cylinder is filled with air from the atmosphere; when the 
piston 11 raises, a partial vacuum is formed under it and 
the pressure of the outside air forces up inlet valve 33 and 
air passes into cylinder. On the arrival of the piston at 
the top of its stroke, both these air valves, 30 and 33, drop 
into their seats, remaining there during the return or 
down stroke. The other set of air valves open on the 
down stroke, 31 to admit air above the piston 32 to dis- 
charge air from the lower end of the air cylinder to the 
main reservoir. 



26 THE AIR PUMP 

When the steam piston reaches the top of its stroke, 
the reversing plate 18 strikes the shoulder n of the revers- 
ing rod 17, moving it up; this in turn moves the reversing 
valve 16 up also. Reversing valve 16 being moved up in 
chamber e covers port a so live steam can no longer pass 
on top of reversing piston 23 ; ports b and c are connected 
by the cavity in valve 16 so that the steam in cavity d over 
piston 23 exhausts through c and balances the pressure 
on each side of piston 23. The top piston of main steam 
valve 7, which has live steam under it, being larger than 
the bottom one and piston 23 being balanced, the main 
steam valve 7 is raised up, also moving up 23\ this move- 
ment of 7 opens the upper steam ports and the lower 
exhaust ports so that live steam pushes the piston 10 
down to the bottom of the cylinder. When the piston 
reaches the bottom of the stroke, the reversing plate 18 
catches on the button x at the bottom end of reversing 
rod 17 and moves the reversing valve back to the position 
shown in the cut; the live steam then moves the piston 
valves 23 and 7 to the positions shown there, and the 
pump is ready for the up stroke. 

The first sectional view of the 9^-inch pump is shown 
with the main piston 65 and all the valves in the steam 
end as they stand when the pump is making the upward 
stroke. The live steam which comes up through passage 
a at the back of the pump into steam chest A is always on 
top of the main slide valve 83. This valve is shown at the 
right hand end of its stroke, in which position it uncovers 
port b so steam can pass down to the bottom end of steam 
cylinder under the piston 65 and push it upward. At the 
same time the exhaust cavity of this slide valve 83 con- 
nects the port c, which opens into the top end of the steam 
cylinder, with exhaust port d, which passes down around 
the back of cylinder to the exhaust pipe; the steam above 
the piston can then pass into the exhaust. This slide valve 
83 is moved by the differential piston valve 76, with the 
large piston 77 on one end and the small piston 79 on the 
other. Chamber E is always connected to the exhaust 




I3|[_ 'LV-^ AIR 

■~-^T| /DISCHARGE 



% ~t^£*8 



28 THE 9^-INCH AIR PUMP 

passage through port t in the side of the main valve bush- 
ing 75 so that this piston has live steam on the steam chest 
side and the exhaust on the other at all times. The large 
piston 77 on this valve 76 has live steam on the steam 
chest side and the office of the reversing valve 72 is to con- 
nect the chamber D at the outside end of 77 with the live 
steam or with the exhaust as may be required to move 76 
back and forth. When D is connected with the exhaust 
both outside ends of the piston valve 76 have no pressure 
on them, the live steam between the heads moves 77, 
which has the greatest area, away from the live steam 
pressure towards the right. When the main steam piston 
63 approaches the top of its stroke the reversing plate 69 
strikes the shoulder / of the reversing rod 71 which is 
moved up carrying the reversing valve 72 up ; this admits 
steam into port g } it passes along the side of the bushing 
through the port shown into chamber D at the outside of 
piston 77, which having live steam on both sides of it is 
balanced. Piston 79 has live steam inside and exhaust 
outside, so it moves away from the live steam drawing the 
main slide valve 83 with it. This movement uncovers port 
c, live steam passes down on top of the piston 65, the 
exhaust cavity of 83 connects port b and exhaust port d 
together and the steam from bottom end of cylinder can 
pass up through passage or port b to the exhaust pipe. 
Steam piston 65 will then make the down stroke. The 
position of all the valves and pistons while the down 
stroke is being made is shown on next page. When close 
to the bottom end of the stroke, the reversing plate 69 
catches the button x on the bottom end of reversing rod 
71, pulls this rod down and with it reversing valve 72, and 
connects chamber D with the exhaust through ports f and 
h in the side of bushing 75. As soon as the pressure is 
relieved, live steam moves piston 77 to the right, drawing 
the main slide valve 83 with it; all steam valves are then 
in the position shown on page 27, and the pump begins the 
upward stroke. The main valve 7 of the 8-inch pump has 
live steam between its two heads or pistons at the same 




AIR > 
DISCHARGE 



104 j 9 i±2 



30 AIR PUMP CAPACITY 

time and this tends to force the main valve up. Piston 23 
is used to overcome the advantage the large piston 7 has 
and force it down for the up stroke of the piston 10. With 
the 9 ^2-inch pump the differential piston 76 is moved by 
changing the pressure on the outside of piston 77; this is 
done by the reversing valve 72. The angling hole in cap 
nuts 20 and 74 serves the same purpose in both pumps — to 
balance the pressure on both ends of the reversing rods ; — 
this opening connects with the top end of steam cylinder, 
down past the reversing valve bushing. The reversing 
valve 72 in the 9^-inch pump performs the same office as 
valve 16 in the 8-inch pump, but the reversing valve 16 
admits steam over the top of 16 through port a to piston 
23, while valve 72 admits steam under the bottom end 
through port g to piston 77. In both pumps the reversing 
rods work the same and have the same class of troubles. 
The arrangement of the steam valves in the 9^-inch pump 
is much superior to that of the 8-inch in every way, and in 
addition they are all located in the top head 60. In case 
the steam valves get out of order, by changing the steam 
head 60 with its reversing rod 71, we get a good pump 
again. 

The air valves in the 9^2-inch pump are all of one size 
and have the same lift — three thirty-seconds of an inch; 
when new they are interchangeable with each other. The 
air valve cages 88 are also interchangeable. As these air 
valves act the same as those of the 8-inch pump when the 
pump is working, an explanation is not necessary. 

This pump is 9^ inches bore and 10 inches stroke; with 
140 pounds of steam it should fill a main reservoir 26 Z A 
inches in diameter by 34 inches long, having a capacity of 
about 15,000 cubic inches from up to 70 pounds in 38 
seconds, or from 20 to 70 pounds in 27 seconds. You can 
determine whether a 9^-inch pump is in good order by 
testing it and noting whether it can do this work. 

An 8-inch pump should pump this amount of air from 
to 70 pounds in 68 seconds, and from 20 to 70 pounds in 
about 50 seconds, using steam at 140 pounds. 



AIR PUMP CAPACITY 31 

The 11-inch pump is much the same in construction as 
the 9^2-inch pump. It is 11 inches bore and 12 inches 
stroke. The air valves are much larger, but have the same 
lift, three thirty-seconds of an inch. Its operation is the 
same, so the explanation for one pump will do for the 
other. The capacity is much greater, as 100 strokes of the 
11-inch pump will compress 48 cubic feet of free air, while 
100 strokes of the 9^-inch pump will compress 36 cubLc 
feet. When working at full capacity the 11-inch pump 
will compress 58 cubic feet of free air per minute and the 
9 ^2-inch pump 38 cubic feet. 

The steam end of the pump is usually oiled by a sight 
feed cup, either a part of the engine cylinder cup or a 
small independent one. The air cylinder can be satis- 
factorily oiled by an attachment to the oil tank of the 
regular cylinder cup — see illustration and description on 
inside of front cover. This sight feed device is a down 
drop through air instead of an up drop through water. 
When operated, the regulating valve at the top is opened 
to feed a few drops at a time, not more than ten, and at 
such intervals as in the judgment of the engineer is 
required. It is not intended for a continuous feed, that 
is liable to give too much, oil, this is as bad as not 
enough. 



MAIN VALVE BUSHING 




This cut shows 
the position of re- 
versing valve 72 
when pump i s 
making the up 
stroke. 

Port g in main 
valve bushing is 
for live steam to 
piston 77: his port 
for exhaust from 
this piston ; ./"con- 
nects with exhaust 
portrf. 



This cut shows 
the position of re- 
versing valve 72 
when pump is 
making the down 
: H stroke. 

See page 28. 




DEFECTS OF THE AIR PUMP 33 



DEFECTS OF THE AIR PUMP 

Many of the break-downs and defects of the air pump 
can not be remedied when away from the "shop, some of 
them can ; it is important to locate the nature of the de- 
fect at once to know if it can be fixed then and there, or if 
another air brake engine will be needed to handle the 
train as well as to be able to properly report the defect 
on the work book. 

In the case of any disability or break down of the 
steam end the pump usually stops altogether. If the air 
end is out of order it will not make any air or at the best 
will work irregularly. We will first take up the disabilities 
which will make the 8-inch pump stop altogether. First 
see that a full supply of steam goes to the pump; if it 
does not the trouble may be in the governor. 

Leaky gaskets in the steam head or leaks past the 
bushings from one port to another will let the live steam 
blow into the exhaust so there is not enough pressure to 
reverse the pump. In such cases you can hear the blow, 
the pump is pretty certain to stop at the bottom end of the 
stroke and stay there. If the copper gasket gets cracked 
at the opening where steam goes through from port h into 
the steam head the live steam can blow on one side into 
the exhaust, on the other into the steam cylinder; this 
leak does not always stop the pump, usually it does. If 
anything works into this port h and stops it up so steam 
can not pass through in sufficient volume to hold proper 
pressure for the reversing piston it will stop. 

Leaks past the bushings are not unusual; when once 
they start, the steam soon finds a way to get to the exhaust 
without doing its work. 

When the packing rings and valves in the steam end 
become worn the oil will blow into the exhaust before it 
has oiled all the moving parts. This will leave reversing 
piston 23 so dry that it will not move and reverse the 
position of main steam valve 7. This is a case where 



34 AIR PUMP DEFECTS 

increasing the feed of oil and jarring the steam head with 
a block of wood will usually start the pump. 

A piston rod broken where it joins piston 23 will act 
much the same way; this rod has been known to get stuck 
in the bottom hole in the bushing and hold the piston 
down. The small hole starting in the side of this bushing 
running down and to the side of this piston rod is to oil 
this rod; if it gets stopped up it should be opened. Some- 
times the top of reversing piston 23 will wear to a steam 
tight fit against the cap nut 21; this keeps the steam off 
the top of piston 23, it can not then push it and main 
steam valve 7 down. An examination of these surfaces, 
and if necessary nicking the smooth surfaces so the steam 
can get in, will remedy this. 

When the reversing plate 18 gets loose, or the button x 
on the reversing valve rod 17 breaks off, the pump will 
reverse at the top end of its stroke, but not at the bottom 
and will stop at the bottom end of its stroke. If the steam 
is now shut off and the reversing valve allowed to settle 
down by gravity when the steam is turned on, the pump 
will make another double stroke and stop again. Taking 
off the cap nut 20 and raising up the reversing rod will 
show whether this is the trouble. In this case a spare rod 
17 comes handy. If the plate 18 is loose the steam head 
will have to come off to get at the plate. If one of the 
nuts '58 holding the air piston on the piston rod works off, 
or a piece of it breaks off — these nuts split sometimes — 
and gets under the air piston so that it can not come clear 
down to move the reversing rod and valve properly, that 
will stop the pump. Take out the plug 59 in the bottom 
head of the air cylinder or the entire head, and this trouble 
can be located. If the nuts work off either end of main 
steam valve 7 the pump is liable to stop at once. If the 
stop pin 50 below the small piston 7 breaks off so the small 
piston gets below the bushing 26 and sticks, the pump 
will stop until this valve can be moved up. 

Stoppage of the pump may be caused by an obstruc- 
tion working into some of the small steam ports, closing 



AIR PUMP DEFECTS 35 

them up, especially port h. Taking off the cap nut 21 
after steam has been shut off and all the valves settled 
down will locate this difficulty, as when all the passages 
are free the steam will come out through port a over the 
reversing piston 23. This same test will show whether 
governor is open for steam but is not as reliable as break- 
ing the joint between the governor and pump. We will 
speak of the governor later on. 

As the reversing rods, plates and valves are of the 
same pattern in the il-inch, 8-inch and 9^4-inch pumps, 
the failures of any of these parts affect all these pumps 
alike. With this exception the steam end of the 9^2-inch 
pump gives very little trouble if the joints and gaskets are 
in good order. 

Nearly all the blows of steam when the pump is at 
work take place when the steam piston is making the 
upward stroke. At that time the steam can blow past the 
steam piston packing rings for when on the down stroke 
the condensed water laying on top of this piston will pre- 
vent much steam getting by the rings ; on the up stroke 
there is nothing of the kind to hold the steam back. On 
the up stroke live steam is on top of reversing piston 23 so 
it can blow into the exhaust, on the down stroke it is ex- 
haust on both sides. With the differential piston 76 of the 
9^-inch exhaust steam is on both ends on up stroke. 

A blow past these main valves of either pump is so 
nearly like a blow past the steam piston that an examina- 
tion is necessary to determine its location. A bad blow 
coming all at once is a good indication of a broken 
packing ring or a leak started through one of the copper 
gaskets. 

If the top end of the reversing rod is not a steam tight 
fit in its cap nut in the 8-inch or 74 in the 9^-inch and 
11-inch pump, steam will blow past there steadily on the up 
stroke; passing through the small hole drilled obliquely 
through the cap nut, then down past the reversing valve 
bushing and into the upper end of steam cylinder which 
on the up stroke is connected to the exhaust It can not 



36 LEAKY AIR VALVES 

blow on the down stroke, as at that time live steam is in 
the top end of the cylinder. Very few of these reversing 
rods are steam tight in the cap nuts. This opening between 
the steam space above the piston and top of cap nut is 
necessary to balance the pressures on the reversing rod 
so it will not move while the pump is making its stroke. 

If the reversing rod gets bent so it catches on the 
reversing plate or the button catches on the side of the 
hole in the piston rod, the pump will reverse before it 
completes its stroke. A pump that reverses too soon in its 
stroke will pump very little air into the main reservoir. 

A difficulty in the air end of the pump will usually give 
notice at once by a quick stroke one way and a slow stroke 
the other, which may be caused by several defects. If air 
from main reservoir leaks past a discharge valve it will 
fill that end of the cylinder with high pressure air so the 
air piston will move away from it quickly and towards it 
slowly. In such a case the inlet valve cannot lift — no air 
will be drawn in at that end. If the inlet valve leaks an 
examination will disclose it with the 8-inch pump. With 
the 9*A and 11-inch pumps it is not so easy, as the air 
passing out of one inlet valve will pass to the other and 
give it the signs of a poor suction there. Improper lift of 
valves will make a pump move faster one way than the 
other. If the lift of an inlet valve is too small, that end of 
the cylinder may not fill with air so the piston will not 
meet with so much resistance in compressing the air. 
If the lift of a delivery valve is too small the piston will 
move very slowly at the last part of the stroke; it has to 
wait for the compressed air to pass through the small 
discharge opening. It will show more difference in 
relative speed when the air pressure is low. 

The lift of the receiving valves 31 and 33 of the 8-inch 
pump should be one-eighth of an inch, of the discharge 
valves 30 and 32 three thirty-seconds of an inch. This lift 
is very soon changed by the wear of the valves and the 
seats; too much lift of discharge valves will make the 
pump pound, as well as wasting main reservoir air by 



AIR PUMP DEFECTS 37 

allowing some of it to flow back into the cylinder before 
the valves can seat. To test for a leak in the bottom 
discharge valve, pump up full pressure, stop the pump, 
take out the plug in the bottom head — air will blow T out 
there steadily from a leak. To test for a leak in top dis- 
charge valve leave this bottom plug out and open the oil 
cup on top end of cylinder; see if air blows out there 
steady; if so, it comes from top valve. You should have 
both ends open as the air might leak past piston packing 
and appear to come from the wrong end. 

Leaky packing rings, leaky valves, choked air passages, 
all tend to make the pump run hot. Running the pump 
at too high a speed is generally the trouble in the first 
instance. When once it has been very hot the packing 
rings contract and do not fill the cylinder; the valve bush- 
ings leak and the oil burns on the inside of passages and 
make a bad matter worse. 

The Westinghouse Company are now making a cross- 
compound air pump in which the high pressure steam 
piston operates the low pressure air piston; the steam 
when exhausted from this cylinder then passes across to 
the other end of the low pressure steam cylinder and 
operates the low pressure steam piston and the high 
pressure air piston. A diagrammatic view of this pump 
is shown ; as by this means the steam and air passages can 
be more clearly traced. The reversing rod 21 and valve 
22 are operated by the reversing plate 18 at the end of the 
stroke of the high pressure steam piston 7 in the same 
manner as the 9 V 2 -inch pump. 

The first design of this pump had a differential piston 
and slide valve to open and close the steam and exhaust 
ports for the steam cylinders ; very few of this pattern 
are in service. A later design has a piston valve instead 
of a differential piston and slide valve. This piston valve 
consists of five pistons, a large one at one end and a small 
one at the other that have the same duties as the differ- 
ential pistons in the other pumps, between these two and 
pistons are three intermediate pistons of the same size 



38 CROSS-COMPOUND AIR PUMP 

that open and close communication between the ports 
leading to and from the steam cylinders. 

The same type of reversing valve is used, except that 
the exhaust cavity is 'near the top, in the old one it is 
near the bottom. 

Steam from the boiler after passing the governor, 
comes in at the side, passes through port a up and across 
the steam head into ports b inside the large piston at 
one end and inside the small piston at the other; the 
diagrammatic view shows all these ports. Live steam also 
passes in at port k around the reversing valve 22. 

As the high pressure steam piston must make at least 
one full stroke before any steam can pass into the low 
pressure cylinder, in this explanation we will consider 
that high pressure piston 7 has made its first up stroke 
moved the reversing valve to its top position and opened 
steam port n so live steam has passed into cylinder D 
and forced piston valve 25 to the left as shown; E at the 
small end is always in connection with the exhaust e 
through port o. Live steam now flows through port c on 
top of piston 7 forcing it down. Steam under piston 7 
that moved it up in making the previous stroke can now 
pass through port g from the bottom of this cylinder up 
into cavity i between the first and second intermediate 
pistons, thence down through port / into the bottom of 
the low pressure cylinder under piston 8, forcing it up; 
any steam above this piston can escape through port d 
and cavity h between the second and third intermediate 
pistons into exhaust port e and the atmosphere. 

When piston 7 is about to complete its down stroke 
it moves the reversing rod and valve down also, this closes 
port n and connects exhaust port m from cylinder D with 
the exhaust port / leading to e so the steam in D escapes 
to the exhaust, live steam pressure in cavity b at once 
moves piston 25 to the right connecting ports c and d 
through cavity h, the steam above piston 7 now passes in 
above piston 8, live steam from b flows through port g 
into the bottom end of high pressure cylinder and piston 



STEAM ££s 
[EXHAUST. 




AIR DISCHARGE. 



40 38 

Diagram of the Cross Compound Pump, Down 
Stroke, High-Pressure- Steam Side. 



40 CROSS-COMPOUND AIR PUMP 

7 makes the up stroke, piston 8 makes the corresponding 
down stroke, the steam below it escaping to the exhaust 
through port -f and cavity i to c. Port s is a balancing 
port to equalize the pressure on the top and bottom of the 
reversing rod 21. 

The low pressure steam cylinder has three by-pass 
grooves in it at each end that are open just as the low 
pressure piston completes its full stroke and allow steam 
to pass around the piston from the pressure side to the 
exhaust side of piston 8. The steam pistons move at the 
same time, but in opposite directions, the high pressure 
piston moves the reversing rod and valve so this piston 
must make a complete stroke each time to operate the 
piston valve 25 and change the course of the live and 
exhaust steam. 

The course of the air through the air cylinders and 
valves from the atmosphere to the low pressure cylinder, 
then across into the high pressure air cylinder is shown 
by the small arrows pointing in the direction the air is 
flowing. When the low pressure air piston 9 made its 
up stroke any air above it was forced out past the upper 
intermediate valves 39 behind the moving high pressure 
piston 10 and air below piston 10 passes out by discharge 
valve 42 to the main reservoir. In the diagrammatic view 
low pressure air piston 9 is shown making the down 
stroke, air from the atmosphere is flowing in at the upper 
air inlet thence by the inlet valves 37 and port s, and fill- 
ing the air cylinder behind the moving piston 9, inter- 
mediate valves 39 prevent any air coming back from the 
high pressure air cylinder. The air below piston 9 is 
now compressed till it will pass out through port t past 
intermediate valves 40 into the high pressure cylinder 
below piston 10 that is making its up stroke; the air above 
it is compressed till it exceeds the main reservoir pressure 
and raises discharge valve 41, passing out through w to 
the main reservoir. 

The inlet and intermediate air valves are double, as 
39 and 40 show, 37 and 38 being set the other way across 



PUMP GOVERNOR 41 

the pump; the sectional view shows only one of the pair. 
During the stroke of the pistons the intermediate pressure 
being that between the low and high pressure air pistons 
reaches about 40 pounds. 

The high pressure steam piston 7 has a diameter of 
§y 2 inches, low pressure steam piston 8 is 14^ inches ; 
all pistons have a stroke of 12 inches. The low pressure 
air piston is 14^ inches and the high pressure air piston 
9 inches in diameter. 

The capacity of this pump is 131 cubic feet of free 
air per minute, as against 58 for the 11-inch pump work- 
ing under the same condition. 



THE PUMP GOVERNOR 

The duty of the pump governor is to shut off the 
steam from the air pump when the air pressure has reached 
the standard desired. Where only one pressure is to be 
controlled, the single governor is used ; if more than one 
pressure, the duplex governor is used. The steam valve 
and its air piston are the same with both the duplex and 
single governors, but one or two air tops are used, accord- 
ing to the number of air pressures controlled. 

It is located close to the pump on the steam pipe, at 
the union connection 70 the air that operates the governor 
enters, and is under the diaphram 67. This diaphram is 
held down by the regulating spring 66, which can be 
adjusted by the regulating nut 65. 

We w T ill suppose that the spring 66 has been adjusted 
to hold the diaphram down against the air pressure of 90 
pounds and no more. When the air pressure exceeds 90 
pounds the, diaphram will be raised against the resistance 
of the spring; this will raise the air valve, air will flow in 
on top of the air piston 53 and' force it down, moving 
steam valve down to its seat and closing the steam sup- 
ply to the pump, which will stop it. 

As soon as the air pressure falls so the regulating 
spring 66 can move the diaphram down and close the air 



42 



PUMP GOVERNOR 



PUMP GOVERNOR 



* DETArLS. 



valve the air pressure above the piston drops, and the 
steam valve is opened allowing the pump to take steam 
again. With the duplex governor the regulating spring of 
one air top can be adjusted for one pressure and the other 
spring for another pressure. Thus the pressure carried 
depends on which side of the governor is in operation. 
There are several causes which will prevent the gov- 
ernor from shutting off the steam from the pump when the 
maximum air pressure is obtained. If the regulating 

spring is screwed down too 
tight it will not allow the 
diaphram to raise and lift 
the air valve off its seat. If 
too much oil is used in air 
end of pump the air valve 
gets gummed up where it 
rests on its seat so air can 
not get through after air 
valve raises. This is the 
most common cause of the 
pressure getting higher 
than the governor is set 
for. To cure this trouble 
take out diaphram and 
clean off air valve and its 
seat so air can get through 
freely when air valve raises- 
If the air leaks past piston 
as fast as it comes through 
air valve, the piston will 
not be moved down as 
there will be no pressure 
above piston. Putting in a 
tight packing ring cures 
this unless the cylinder is 
worn out of true. If the governor piston sticks so air 
pressure will not force it down, steam will not be shut 
off. If the waste pipe in the side of steam end of gov- 



50. Steam- Valve Body 

51. Steam Valve. 

52. Cylinder Cap. 

53. Governor Piston 
04. Piston Packing Ring.65- 
f>5. Governor-Piston Nut. 
36. . Governor-Piston Spring 1 
57. Strain - Valve Cylinder 

6ir- Diaphragm Body. 

63. Spwng Box. 

61 Cap Nut. 

65. Regulating Nut. 

66. Regulating Spring. 
ty7. Diaphragm complete; 

*£$, Diaphragm Ring. 




PUMP GOVERNOR 43 

ernor is stopped up so steam or air is confined below 
piston, the governor will not shut off at any pressure. 
This waste pipe may be smashed out flat so nothing can 
pass through it, in cold weather it will freeze solid full 
at the bottom end which will keep the air piston held up. 
If anything gets in over diaphram so it cannot raise, that 
will hold air valve shut so air cannot get on piston to shut 
off steam valve. If valves and seats are kept clean, and 
all parts allowed to move as they should, governor will 
work accurately. In case the governor shuts off the steam 
with less than the standard pressure you are likely to find 
there is dirt or a scale holding the air valve off its seat 
so air can get through on top of piston steadily, in which 
case the governor will shut off steam as soon as air 
pressure on the top of governor piston will more than 
balance steam pressure on steam valve. If this air valve 
seat is injured so it leaks, or a new valve has been put in 
that is too short to make a good joint, a very low air 
pressure, less than forty pounds, will shut off the steam. 
A broken regulating spring will also do this. 

Sometimes the pump will not start up soon after the 
air pressure in the governor has been reduced below that 
the governor diaphram is set at. This is because when the 
air valve closes, the air is shut up in cylinder over gov- 
ernor piston and must leak out before piston can raise and 
open steam valve. The old type of governor D-9 had this 
trouble, but the new style of governor E-8 has a small 
blow hole drilled in the side of 62, below air valve seat, 
which lets enough air escape after standard pressure is 
reached to keep pump running steadily. 

To find if the trouble is in the governor when the 
pump will not start, open both drip cocks in the 9^2-inch 
or 11-inch pumps, or break the joint between the governor 
and 8-inch pump; if live steam comes out freely the gov- 
ernor is not at fault. In such a case shut off steam at the 
boiler, wait a few seconds till steam is out of pump and 
turn it on again, if the live steam blows out freely, the 
trouble is in the pump. 



44 PUMP GOVERNOR 

With the single top governor and a brake valve using a 
feed valve to regulate the brake pipe pressure, main reser- 
voir air is used to operate the governor, with some types 
of brake valves like the old D-8 or the N. Y. brake valve 
brake pipe pressure operates the governor. With the 
duplex governor one side is usually piped to the main 
reservoir direct, the other side, in some cases, uses brake 
pipe air. With the high speed brake, one side is set for 
90 pounds, the main reservoir pressure used with the 
ordinary brake pipe pressure of 70 pounds ; the other side 
for the higher pressure needed to release brakes, using 
110 pounds. In such cases there is a stop cock in the 90 
pound side air pipe, which is to be closed to cut out that 
side when the higher pressure is used. The N. Y. brake 
uses a triple governor. 

There is also a method of piping which allows of two 
main reservoir pressures being used, one on release and 
running position of the F-6 brake valve and a higher one 
with the valve on lap and application positions. The 90 
pound side is piped to the port / in the 1892 model brake 
valve at a point just above the figure 62 — see the cut of 
this valve farther on. When the rotary is in full release 
or running position, main reservoir air can come freely 
into this port and operate the governor at a pressure of 
90 pounds. During a brake application this port / is closed 
by the rotary and the air pressure there soon equalizes 
with the brake pipe. 

The 90 pound side of the governor does not then con- 
trol the pump and the high pressure side which is con- 
nected directly to the main reservoir and adjusted for a 
pressure higher than 90 pounds, usually 110 pounds, allows 
the pump to run and raise the main reservoir pressure so 
as to have a good stiff excess to release brakes. 

There is also a method of piping the S F duplex gov- 
ernor with the E. T. brake to control the amount of excess 
pressure regardless of what the brake pipe pressure may 
be. One side is piped to the main reservoir direct at 
MR, and set 120 or 130 pounds, according to what the 



PUMP GOVERNOR 



45 



maximum main reservoir pressure is to be. The other 
side has a light spring 27 over the diaphram that has the 
proper tension to hold the diaphram 21 down for the 








THE SF=4 PUMP GOVERNOR 



excess desired. At A B V main reservoir air from the 
brake valve comes in under the diaphram at d from the 
automatic brake valve in full release, running and holding 
positions. The position of the brake valve regulates the 
flow of air to the excess pressure side. At FVP feed valve 
air at the reduced pressure comes in above the diaphram, 
and its pressure is added to that of the spring 27 so that 
we have 70 pounds brake pipe plus that of the spring — 
say 20 pounds — so that when the main reservoir air in d 



46 PUMP GOVERNOR 

can overbalance the presure of 70-^20 above the diaphram, 
the diaphram will raise the pin valve and admit air over 
the governor piston and close the steam valve 5, This 
will operate the same at any other brake pipe pressure; 
so there will be the same excess, depending on the adjust- 
ment of the spring 27. Air passes in at ABV only in 
release, running and holding positions of the type H 
brake valve. When the brake valve is moved to lap or 
beyond the air is cut off from under the diaphram at d 
and the pressure at a and spring 19 control the pump. 
A peculiarity of operation of this governor is that when 
charging up a long train through the brake valve in run- 
ning position, if there is more than 20 pounds difference 
between main reservoir and brake pipe pressures the gov- 
ernor will stop the pump. In such a case put the brake 
valve in full release and the pump will soon start. 



AIR BRAKE CATECHISM 



1. Q. What are the essential parts of the automatic 
brake and what service does each part perform? 

A. The air pump, the main reservoir, the engineer's, 
brake valves, automatic, independent and straight air, the 
brake pipe with its hose, couplings, and angle cocks, the 
auxiliary reservoir, the triple valve, the brake cylinder, 
the gage and the pump governor. The air pump com- 
presses the air for setting and releasing the brake; the 
main reservoir is used to store a supply of air for charging 
the brake pipe and auxiliary reservoirs when empty, as well 
as to hold the supply for increasing the brake pipe pressure 
when the brake is to be released and to charge the brake 
pipe and auxiliaries ready for the next application; the 
automatic brake valve governs the passage of the air from 
the main reservoir to the brake pipe, from the brake pipe 
to the atmosphere, or stops the flow of air through it in 
any direction. The brake can be set gradually or full on, 
held set or released, when this valve is properly handled 
by the engineer. The feed valve controls the supply of air 
to the brake pipe in running position of brake valve and 
regulates its pressure; the straight air brake valve passes 
main reservoir air, reduced to 45 pounds, to and from the 
brake cylinders direct. The brake pipe, with its hose and 
couplings, extends from the brake valve, to the last air 
brake car, and supplies each auxiliary reservoir with air 
for setting the brake. It is also a means of communication 
from the engineer's brake valve to each triple valve, and 
from one triple valve to another in the quick action or 
emergency application. 

Each brake has an auxiliary reservoir in which the air 
is stored for operating it to set. The triple valve consists 
of three separate valves and is connected to the brake 
pipe, auxiliary and brake cylinder; it is used to control 
the charging of the auxiliary with air and regulate the time 



48 INSPECTION AT ENGINE HOUSE 

in which this is done, to open a valve to admit air from 
auxiliary to brake cylinder to set the brake, or by another 
movement to close this valve and open the exhaust port 
so air can get out of brake cylinder to the atmosphere and 
release the brake. Thus the functions of the triple valve 
are three-fold, to charge the auxiliary, set the brake and 
release it. The triple valve is operated by a variation of 
pressures between the brake pipe and auxiliary; this varia- 
tion is controlled by the brake valve. The brake cylinder, 
with its piston connected to the brake levers, beams and 
shoes, sets the brake when the triple valve lets air into it. 
The gage shows with the red hand main reservoir press- 
ure, with black hand pressure in the brake valve above 
the equalizing piston and in brake valve reservoir ; when 
brake valve is in full release, running, or holding position 
it also shows brake pipe pressure. The pump governor 
is located in the steam pipe to pump ; it is operated by air 
pressure and shuts off steam from the pump when the air 
pressure reaches the standard amount carried. 

In addition to these essential parts there is the pressure 
retaining valve that is attached to the exhaust outlet of 
the triple valve and controls the flow of air away from the 
brake cylinder when the triple valve is in release position; 
the conductor's valve that when opened reduces the brake 
pipe pressure and applies the brake, the release valve or 
rjleeder connected to the auxiliary reservoir used to reduce 
the auxiliary pressure and release a single brake. A 
separate valve and its reservoir called the distributing 
valve is used on locomotives and performs the duties of 
the triple valve by applying and releasing the locomotive 
brake. A high speed reducing valve is used on coaches. 

2. Q. What are the duties of an engineer as to his air 
brake equipment when leaving the roundhouse? 

A. To start his pump slowly and increase its speed 
after 15 or 20 pounds of air have picked up ; to be sure 
that pump is in good order and will pump a full supply 
of air promptly; to know that governor shuts off the 
pump when the proper pressure is reached and not before, 



TESTING FOR LEAKS 4$ 

and allows it to start promptly; to see that lubricator has 
oil enough in it for the trip ; to know that there is no 
water in the main reservoir, drain cup, triple valves, 
auxiliary reservoirs or distributing valve, to test all joints 
in piping, also brake valve and triple valves for leaks, 
and have leaks made tight; to see that tender and driver 
brake pistons have the proper travel and do not leak off" 
when set; to test the air signal if one is used. 

3. Q. Why must the pump be started slowly, oil used 
cautiously, triple valves, reservoirs and tender strainers be 
drained, and how often? 

A. The pump must be started slowly to allow the 
condensed water to get out of steam end, and run slowly 
till the air pressure rises, or the piston will strike the 
heads of air cylinder. The triple valves, reservoirs and 
strainers, or drain cups, should be drained every day in 
cold weather, once a week in warm weather. Oil should 
be used sparingly in air end of pump. It should never be 
put in through the air inlets of the pump, as it soon 
collects dirt and chokes up the air passages, which helps 
to make the pump run hot. 

4. Q. How do you test for leaks in the engine equip- 
ment? 

A. When full pressure is obtained — 70 in brake pipe, 
90 in main reservoir — shut off pump, place valve on lap ; 
if red hand drops and black hand is stationary, it is a sign 
of a leak somewhere in main reservoir line, which begins 
at valves in pump and ends at brake valve. It may be in 
joints of piping, in main reservoir drip plug, in the air 
signal line, in valves of pump or brake valve. If there is 
an air sander or air bell ringer on the engine their valves 
are liable to leak. If main reservoir pressure falls rapidly 
when you are sure it is not going into brake pipe under 
rotary, examine each of the places mentioned. With the 
use of the cut-out cock under brake valve a leak under 
rotary is soon detected. Set the brake full on, place the 
valve on lap, shut the cut-out cock ; if rotary leaks into 
brake pipe the black hand will soon show same pressure- 



50 TESTING FOR LEAKS 

red one does ; if rotary is tight and air leaks out of brake 
pipe the black hand will drop. With a leak in brake pipe 
of engine or tender and cut-out cock shut, the brake will 
set with valve on lap, and cut-out cock open the black hand 
will fall slowly. For a leak in signal line shut the cut- 
out cock next the reducing valve; a leak here will make 
the whistle blow. Using a torch or putting soapsuds on 
a suspected leak will generally locate air blowing out 
there. 

5. Q. Why must there be no leaks in your brake pipe 
or any other part of your air brake supply? 

A. If brake pipe leaks, brake will continue to set 
tighter when brake valve is put on lap, and stop the train 
oefore you want it to, so that it is necessary to let it off 
and make another application for an ordinary stop. If 
cars are cut off from engine, they must be bled at once if 
their brake pipe or angle cocks leak. Brake pipes some- 
times get worn through where they rest or rub against 
something, so they are tight when standing still and leak 
when moving or shaken around. This leak sets the brake 
when train is in motion, and no leak can be heard when 
standing still. Jar the pipes a little when inspecting the 
engine to locate this leak. Sometimes the brake levers 
strike the end of plug in stop cock and push it in so it will 
leak when brake is applied. 

6. Q. Why must all hose couplings be hung up prop- 
erly when not in use? Why should they always be blown 
out at rear of tender before uniting to other couplings? 
What is the difference between an air brake and an air 
-signal coupling? 

A. So no dirt or foreign matter will get into the Open 
coupling and work into the triple or brake valve or stop 
xip strainers. So couplings and gaskets will not get injured 
or broken dragging over rails and crossings. If blown 
out each time, any water, sand or dirt in the tender piping 
will be blown out. Air brake and air signal couplings are 
of different sizes — made so purposely — so the brake line 
•cannot be coupled to the signal line. The opening and lip 



TESTING FOR LEAKS 51 

of the lock in brake coupling is much wider than the signal 
coupling, so the brake coupling will not go into it. It is 
the practice to paint the signal couplings red so they are 
more easily distinguished when taking hold of them to 
couple up. 

7. Q. If main reservoir has water in it, how will it 
affect the operation of the brake ? 

A. The water in main reservoir reduces the supply of 
air stored there in proportion to the amount of water con- 
tained. The brake will set the same, but on a long train 
will not release as readily, as there will not be enough air 
stored to recharge the brake pipe quickly and you must 
wait to have it pumped. The main reservoir should be 
entirely clear of water, even if it is necessary to drain it 
each trip, so as to get a prompt release and recharging 
of train. 

8. Q. How does this water get into the main reserv- 
voir? 

A. The air from the atmosphere before compression 
contains more or less moisture in the shape of vapor. 
After compression the air can not hold all this vapor as it 
is compressed to a very much smaller volume, so nearly all 
the vapor falls to the bottom of the main reservoir as solid 
water as soon as the air cools of! to the normal tempera- 
ture of the outside air. If the pump runs hot so the air 
does not cool off in the main reservoir some of the water 
will be found in the triple valves and drain cups. 

9. Q. Of what use is the extra main reservoir press- 
ure, and does the size of the reservoir have anything to 
do with the amount of excess pressure you carry? 

A. It recharges the brake pipe and forces the triple 
pistons up into exhaust position quicker and surer, so 
that all brakes release about the same instant; recharges 
the auxiliary to full pressure in less time, ready for the 
next application. With a large main reservoir there is a 
greater volume of compressed air stored to draw from, 
so a less number of pounds of excess pressure will do the 
work than with a small reservoir. With a short train 



52 EXCESS PRESSURE 

good work can be done with less excess than on a long 
train. Excess pressure, as well as a large volume of 
stored air, is needed on a long train, so the air will travel 
from the engine to the rear car more quickly and release 
the rear brakes at nearly the same instant the front ones 
release; this will avoid many break-in-twos. Excess is 
needed to release brakes and large volume to hold up the 
pressure in brake pipe for recharging. The main reser- 
voir should always be drained of water so it will be full 
sized. 

10. Q. Could it release the brakes with an empty 
brake pipe as readily as when the pressure in the brake 
pipe had been reduced only 20 or 25 pounds? Why? 

A. No. When the air from the main reservoir ex- 
pands into an empty brake pipe, it will not fill it up and 
equalize at as high a pressure as when the brake pipe has 
some compressed air left in it. For instance, the brake 
pipe line of 25 freight cars holds 16,000 cubic inches, 
about as many cubic inches of air as an ordinary main 
reservoir. If this brake pipe is entirely empty and the 
main reservoir has 90 pounds, it will equalize into twice 
the space, and show half the pressure, or 45 pounds in 
each. The brake would be set at 50 pounds; with that 
pressure above triple piston, brakes could not release until 
the pump had raised the pressure over five pounds. Now, 
if the brake pipe line has been reduced 25 pounds, having 
45 pounds still left in it, 90 in main reservoir and 45 in 
brake pipe, would equalize at a little over 65, which would 
raise triple pistons so brakes would release promptly. 

11. Q. Would you run your pump as fast to recharge 
an empty brake pipe as one with 45 or 50 pounds in it? 
Is there any economy in retaining as much air as possible 
and keeping the pump cool? 

A. The pump would have to run faster to recharge an 
empty brake pipe than one with 45 or 50 pounds in it. 
When you empty the brake pipe of 25 cars it wastes as 
much air as when you empty a small main reservoir; 
smaller trains in proportion. This would make some 



EXCESS PRESSURE . 53 

pumps hot to supply. Always save your air and keep the 
pump cool, no matter what length of train you handle. 

.12. Q. Please explain what excess pressure is. 

A. Excess pressure is the difference between the main 
reservoir and brake pipe pressures when the brake valve is 
in running position so that the excess valve or the feed 
\ alve can maintain a difference between the two press- 
ures. In full release position these valves are cut out, 
but the air can pass through an open port from the main 
reservoir to the brake pipe and equalize, so in release 
position there is no excess. If you carry excess you aim 
to prevent this equalization and thus have a greater 
amount of air in main reservoir to equalize into brake 
pipe when necessary to release brakes. Of course it takes 
more excess to promptly release all the brakes on a long 
train than a short one. When releasing brake, it supplies 
the brake pipe with a higher pressure than brake was first 
set at; this makes the movement of all triples to release 
position much quicker and surer. With a long train it is 
absolutely necessary for this purpose. On a long train 
excess is needed to force the air back through brake pipe 
quickly and release brakes, with large volume to hold the 
pressure up. It recharges the auxiliaries quicker, ready 
for the next application of the brake. It charges empty 
cars quicker that are taken on the train. When brakes 
"creep on," they can be released at once by placing the 
brake valve on full release for a second or two, just 
long enough to raise the triple to exhaust position and 
not long enough to charge the reservoirs to a higher press- 
ure, then returning it to running position. 

13. Q. Have we more than one pattern of equalizing 
discharge brake valve? 

A. Yes, we have several kinds of them in service, 
called E-6, or F-6, D-8, H-5, and H-6, from the number 
of the plate on which each is illustrated in the Westing- 
house catalogue. The E-6 and F-6 valves are exactly 
alike and are now known as the "1892 model'' or F-6 
valve. Verv few of the D-8 valves are now in service. 



54 THE BRAKE VALVE 

The H-5 and H-6 brake valves came next after the F-6 
or 1892 model, and may be styled the 1906 model. 

14. Q. Describe the principle on which it operates 
and what difference there is between the patterns. 

A. This brake valve has a rotary valve with various 
ports and cavities in it by which the air can pass to and 
from the various pipes and connections when the engineer 
moves the rotary. It also has a piston in it called the 
equalizing piston, with a brake pipe exhaust valve on the 
bottom side of it which is designed to automatically re- 
duce the brake pipe pressure. When brake valve is not 
being operated this piston has an equal pressure on both 
sides of it, so it remains stationary, holding brake pipe 
exhaust valve closed. When it is used to set the brake, 
the reduction of air pressure is not made by the engineer 
direct from the brake pipe, but from the chamber in the 
valve over the equalizing piston and the small reservoir 
connected to the chamber. If the engineer wishes to re- 
duce the brake pipe pressure any specified amount — say 
seven pounds — he moves the rotary to service application 
position. As the rotary passes lap position, the ports 
which allow the air to pass from one part of the brake 
valve to another are all closed. The main reservoir air 
is held on top of the rotary as it is not used when the 
brake is set, but only when releasing or charging the 
brake pipe and auxiliary reservoirs. The air above the 
equalizing piston and the brake valve reservoir being cut 
off from all other air may be called brake valve air, it is 
what operates the automatic part of the brake valve to 
equalize the discharge of the brake pipe air, which is 
below the piston. When the pressure of the brake valve 
air is reduced by allowing some of it to escape from the 
preliminary exhaust port, it does not reduce the brake 
pipe air through the same opening; so the equalizing 
piston having less pressure above it, raises up, opening 
the brake pipe exhaust valve on the bottom of this piston 
and air flows out of the brake pipe. As soon as the brake 
valve air is reduced the amount the engineer wishes (and 



THE BRAKE VALVE 



the amount of the reduction is shown with the black hand 
of gage) he closes the preliminary exhaust port by a 
movement of the rotary to lap. The pressure of the brake 
valve air then remains stationary; while the brake pipe 
air flows out through the brake pipe exhaust till it is 
reduced a little lower than the brake valve air, which then 
moves the piston down gradually and closes the brake pipe 

EQUALIZING DISCHARGE VALVE 

With Feed Valve Attachment. 

1892 Model. 



BRAKE l/ALVE 
Running 
Position 




Plate D 5 Plate E'6. 
and Plate F6. 

These Brake l/a/res arc 
q/ike irr construction 
one/ ope rat/on. 



Feeo Vtiyi 



exhaust. It takes ■ longer to reduce pressure in a long 
brake pipe than in a short one through the small brake 
pipe exhaust port because of the greater volume of air in 



56 



THE BRAKE VALVE 



the long pipe, so the brake pipe exhaust is held open by 
the brake pipe air till the pressure is reduced the whole 
length, then closed automatically by the pressure of the 
brake valve air. 

Each of these valves uses a double hand gage and has 
a small reservoir about 12 inches long connected to it by 



lb Pump Coverkor 8k Gauge 
-red hand- 
MajN Reservo* Pressure 




Feeu V*lve 



a small pipe; this equalizing reservoir is used to supply 
the cavity over equalizing piston with a larger volume of 
air, so a more gradual reduction of pressure can be made 
through the preliminary exhaust port from this cavity. 
The later size of this reservoir is 14^2 inches long; it con- 
tains a larger volume of air than those first used and 
thus makes the reduction of brake valve air more gradual. 
The F-6 has a reducing or feed valve attached, which 
is set to regulate the brake pipe pressure at not over 70 
pounds, at which pressure it closes and no more air can 
pass to brake pipe from main reservoir till the brake pipe 
pressure falls below what the feed valve is set at, when it 



THE FEED VALVE ."> i 

opens again; with this valve the governor is piped to main 
reservoir and set at ninety pounds. 

Either of these valves when placed on emergencv 
position opens a large port which lets the air from the 
brake pipe direct to the atmosphere, making a sudden 
reduction, which causes the brake to go on suddenly and 
with full force. 

15. Q. Describe the feed valve or brake pipe pressure 
regulator. How many kinds are in use and what are the 
differences in their operation? 

A. There are three forms of the feed valve in general 
use. The older one, called F-6. has a poppet valve, 63, 
which is opened and closed by the movement of a piston, 
74, which piston is moved in one direction, down, by the 
pressure of the brake pipe air, and up by a regulating 
spring, 68. 

When the feed valve 63 is open, as shown in the illus- 
tration, the main reservoir air which comes from the 
brake valve when in running position, comes through f, 
passes by valve 63 into cavity B, as shown by the arrow, 
and out through port i into the brake pipe. Piston 74 is 
held up against the brake pipe pressure in B by the regu- 
lating spring 68, which is adjusted to hold the piston up 
so the supply valve will not close till the pressure reaches 
the standard amount, usually seventy pounds; at which 
pressure the piston is moved down far enough to allow 
valve 63 to close on its seat and shut off the supply of 
main reservoir air passing into the brake pipe. 

If from any cause the brake pipe pressure is reduced 
below the standard amount, the regulating spring pushes 
the piston and valve 63 up, so that air passes from the 
main reservoir to the brake pipe. This action of the feed 
valve maintains the pressure in the brake pipe at the 
standard amount steadily, provided there is enough in the 
main reservoir. 

The brake pipe pressure begins to move the piston 
down against the stiffness of the regulating spring at about 
forty-five pounds, so that valve 63 begins to close a little 



58 



F-6 FEED VALVE 



at that pressure. As the pressure increases it compresses 
the spring more, until at seventy pounds piston 74 is down 
so the valve 63 has entirely closed. On account of this 




FEED VALVE OPE/tf 



FEEO V&JLVECJLOSED 



action of the F-6 feed valve the passage of air from the 
main reservoir to the brake pipe was free up to forty- 
five or fifty pounds, and was then gradually restricted as 
the pressure raised, so that between sixty-five and seventy 
pounds the opening was so small that with a long train 
or much leakage it took a long time to feed up between 
those pressures. 

To stop the piston in case the brake valve is in full 
release position, the lower part of the piston comes against 
the top part of the spring case 69, in the illustration the 
piston is shown in this position, in service it moves down 
only far enough to allow valve 63 to close. The small 



F-6 FEED VALVE DEFECTS 59 

spring 64 closes the valve when the piston moves down. 

The two gaskets 72 are intended to stop any brake 
pipe air leaking by the piston. There is a recess in bush- 
ing ring 75 deep enough to hold the smaller gasket when 
the piston is down. If this gasket is too thick for this 
recess it will hold up piston and feed valve so that brake 
pipe pressure will get too high. ' If spring case 69 is 
screwed up too far into valve body 62, the edge of the 
larger gasket will be smashed out thin, the two gaskets 
will then fill the recess in 75 and hold the piston up and 
valve 63 open, which will allow brake pipe pressure to 
feed up too high. 

If the stem of valve 63 that runs up into the cap nut 
65 gets bent, the valve will not seat squarely, and air will 
leak past it steadily. 

A leak through the gasket 56 from port f to port i will 
allow air to pass from the main reservoir to brake pipe 
without passing valve 63. 

Do not confound this leak with a leak through gasket 
61 in the brake valve, which allows the air from main 
reservoir to flow into chamber D in any position except 
full release. A leak through the feed valve affects the 
pressures in running position only, as that is the only 
position in which air can pass the rotary to the feed valve. 

The feed valve attachment must be kept clean if it is 
expected to work correctly. If the valve 63 gets gummy 
so that it is not air tight on its seat, the main reservoir 
will tend to equalize with the brake pipe at more than the 
standard amount. 

The Slide Valve Feed Valve, G-6, which is a later type 
than the F-6, is show r n in two positions, has a slide valve 
55, to open and close the air supply port b, and allow air 
to pass from the main reservoir to the brake pipe when 
the rotary is in running position. This supply valve is 
operated by a piston, 54, which is moved in one direction 
by the main reservoir air pressure, in the other by a 
spring, 58. 

To aid the reader we have prepared two sketches of 



60 



G-6 FEED VALVE 



this feed valve in which the parts and passages are shown 
in such relations to each other that the flow of air through 
the complete valve may be more easily understood. 

With the G-6 feed valve the pressure of the main 
reservoir air against the piston, 54, must be sufficient to 
push it over against the strength of the spring 58, before 
the slide valve will be moved to uncover port b. With 
this valve at work feeding up the brake pipe the main 
reservoir will show slight excess pressure at all times. 
This you do not see with the F-6 valve, as its feed valve 
is not held open by the main reservoir pressure. 

Main reservoir air enters at f, passes into the slide 
valve chamber F on top of, around the ends and sides of 



Suide v*c~e Feed v^lvc 
OPEN POSITION 



Slide-Val/vje Feeo V^lve. 
CLOSED POSITION 




valve 55 and against piston 54. Chamber E, on the other 
side of the piston, is connected through passage c with the 
chamber around regulating valve 59, and if this valve is 
open, air from E will pass through a into the brake pipe 



G-6 FEED VALVE 61 

through i, so that air in E can equalize with that in the 
brake pipe. 

A diaphram, 57, which consists of two thin brass sheets 
keeps the brake pipe air from escaping to the atmosphere 
through the spring case, this diaphram rests on a piston, 
64, which is held up by the regulating spring 67. T he- 
stem of the regulating valve 59, rests against this dia- 
phram, when 57 moves over, the regulating valve moves 
with it. With reservoir pressure in F and brake pipe 
pressure in E, the piston and slide valve moves from the 
position shown in Fig. 4 to that shown in Fig. 3, so that 
the port is open at b, allowing air to pass from / to L 
Piston 54 is not a tight fit in its bushing, while the main 
reservoir pressure is holding it over against the spring 
58, air is leaking by the piston steadily from F into E and 
thence through passage c, past the regulating valve and 
passage a into the brake pipe; in addition to what goes 
in at port b so that air is feeding into the brake pipe 
through two passages b and c. 

When brake pipe pressure reaches the standard amount 
it has moved the diaphram and its piston over against the 
resistance of spring 67 and allowed valve 59 to seat as 
shown in Fig 4. This stops the passage of air from E 
to brake pipe, piston 54 not being an air tight fit, air 
from F soon equalizes with E. Spring 58, which was 
compressed when the piston moved towards E, now 
reacts, pushes 54 and 55 back into position shown in Fig. 
4, this stops the flow of air through b into the brake pipe, 
as the regulating valve has stopped the flow of air from 
E, no more air passes in at either place, and brake pipe 
pressure will not rise any higher. When brake pipe 
pressure falls below the standard amount, the regulating 
spring will move the piston 64 and diaphram enough to 
unseat valve 59, air in E can then equalize with brake pipe, 
reservoir pressure in F at once moves the piston and slide 
valve as shown in Fig. 3 and air feeds into brake pipe 
again. 

If the regulating valve leaks, if either of the cap nuts 



62 



B-6 FEED VALVE 



53 or 61 leak, or if the spring 58 is too weak, or gone, the 
piston will hold slide valve open so that brake pipe press- 
ure may get too high. If the opening by the seat of the 
regulating valve is stopped up, or the regulating spring is 
too weak, the slide valve will be closed. To clean valve 
59 leave rotary in service position and take off cap nut 61. 
To clean piston 54 remove cap nut 53. Piston 54 has no 
packing rings, it should be clean and free from gum. 

If the feed valve is dirty and gummed up it will act 
so slowly that the head brakes are apt to creep on when 
you go to running position after a release. 

The B-6 feed valve is much the same as the G-6, the 
first ones B-4 had a small port drilled through the piston 
8 and a packing ring 9, that regulates the supply of main 
reservoir air passing into the chamber G behind the 
piston. The later valves B-6 do not have this air port 
and packing ring. In all respects the operation of the 
piston with its supply valve, and the regulating valve is 
the same as the G-6 feed valve. But there is a quick 




DIAGRAM OF B^ FEED VALVE, CLOSED 



DIAGRAM OF B^6 FEED VALVE, OPEN 



thread screw on the regulating nut 23 that allows a change 
to be made in the tension of the regulating spring 18 so 
that the pressure of the brake pipe air can be changed 



REGULATING THE FEED VALVE 63 

from 70 to 110 pounds, or vice versa, by a partial revolu- 
tion of the small hand wheel that is part of the regulating 
nut 23. Secured to the spring case 19 are two split rings. 

20 and 21, a small screw 22 binds the ends of the split 
ring when once adjusted so it cannot slip around on the 
spring case 19. The feed valve is first adjusted to close 
at the lower pressure, say 70 pounds, and the split ring 

21 brought against the pin fixed in the hand wheel 23. 
The wheel and adjusting nut 23 are now turned to in- 
crease the tension on the spring 18 till the valve will close 
at the higher pressure, say 110 pounds, and the split ring 

22 is moved against the other side of the pin in 23. By 
turning 23 so the pin rests against one or the other of 
the stops on the rings 21 or 22, the tension of the spring 
is adjusted for the proper pressures. This type of feed 
valve is usually attached to a pipe bracket, as shown in 
the cut, but it can be attached to the 1892 model valve the 
same as the G-6 feed valve. When so used it will do 
away with the pipe bracket, the reversing cock and one of 
the two G-6 feed valves used with the high speed brake. 

16. Q. What pressure does the black hand of the 
double gage show, and why? 

A. It shows the pressure in chamber D above the 
equalizing piston in the brake valve, and in the brake 
valve reservoir, it is connected to the pipe from chamber 
D to the small reservoir and not to the brake pipe. It is 
connected in this manner because when applying the 
brake the engineer must know exactly how much he re- 
duces the brake valve pressure over the equalizing piston, 
therefore the black hand must show the exact pressure 
there while making a service reduction. If the brake is 
set with a direct or emergency application the gage does 
not at once show the exact brake pipe reduction. 

17. Q. In what position of brake valve does it also 
show the exact brake pipe pressure? 

A. Full release, running position, or anywhere between 
full release and lap. In these positions the equalizing 
port g which is the communication between the brake pipe 



64 BLACK HAND PRESSURE 

and the chamber D, is open. In any other position this 
port is shut to the brake pipe pressure so it is not con- 
nected to the black hand direct. 

18. Q. Then the black hand does not show the exact 
brake pipe pressure when on lap or past lap towards the 
emergency position? 

A. No, not immediately, and you can easily prove 
this by placing the valve on lap and opening the angle 
cock at rear end of tender ; the brake pipe pressure will 
drop to nothing at once, which the black hand will not 
do. Usually the equalizing piston packing ring leaks a 
little, and the black hand will drop back slowly as the air 
leaks out into the empty brake pipe; if there are no leaks 
in the brake valve, or connections to gage or brake valve 
reservoir, it will not drop any. Unless the packing ring 
leaks considerable it does little harm. A very small leak 
is an advantage as it will show on the black hand the 
brake pipe pressure as soon as the pressures can equalize 
past the piston, it can warn the engineer if valve is left 
on lap and brake pipe pressure falls slowly without setting 
the brake. 

If the air in the brake pipe and chamber D can equalize 
past piston 47 the black hand will show brake pipe press- 
ure; when auxiliaries have equalized with brake pipe, it 
will show both pressures. 

19. Q. When the brake valve has been left on release 
position till brake pipe and main reservoir have equalized 
at seventy pounds, and is then placed on running position, 
are the brakes apt to creep on at once? Why is this? 

A. When the valve is placed on running position, it 
shuts off the air from brake pipe till the excess pressure 
is picked up in the main reservoir to force the air past 
feed valve; before this excess is picked up if the brake 
pipe leaks, the brake will set. In such a case, run your 
pump a little faster for a few minutes — not over five — 
so as to get the excess quicker. If train is under motion 
and you feel a brake dragging, put the brake valve in full 
release for a second only, then place it in running posi- 



BRAKE VALVE POSITIONS 65 

tion ; this may have to be done a second or third time 
until air begins to go through feed valve, when it will 
hold brakes off. A short rule for this is: Keep your 
excess all the time by not using the full release position, 
except at the time of releasing the brakes, then running 
position will hold them off. 

20. Q. Please state the different positions of the brake 
valve, the course the air takes passing through it, and 
what ports are covered in each position. 

Note — To aid the student we have prepared some 
sketches of the D-8 brake valve that form its construc- 
tion and is more easily explained than the later valves, in 
which the rotary 13 is shown as if it were a long valve 
sliding in a straight line back and forth over a valve seat 
instead of turning on a center as the actual rotary valve 
really does. In these sketches the rotary is shown as if 
cut between the preliminary exhaust cavity p and the 
emergency exhaust cavity and straightened out as a hoop 
is straightened out when cut across. The ports are shown 
in somewhat changed positions so they will be in proper 
communication with the ports and cavities in the sliding 
valve 13. Ports a and g are shown in the sketch as if 
they communicated with each other, in the actual rotary 
valve a is nearer the center than g, so in service they do 
not register with each other. In actual service port / 
registers with / in running position as shown, and with 
port g in emergency position ; but for the purposes of ex- 
planation the sketch gives a very good idea of the course 
of the air in the various positions of the D-8 valve. 

A. When on full release position, main reservoir air 
which comes in the brake valve on top of the rotary can 
pass through opening a in the rotary into a cavity in 
the rotary valve seat b and from there around the bridge 
in rotary and into the brake pipe direct; in this position 
the main feservoir and brake pipe pressures can equalize. 
The air from main reservoir also passes through the feed 
port ; in rotary valve into the supply port e for the pre- 
liminary exhaust and down into chamber D. Air can also 



Full pel ease 




Running S Position % 




DIAGRAMMATIC BRAKE VALVE 



67 



pass into chamber D from the brake pipe cavity c in rotary 
valve through equalizing port g. In this position the 
warning port is open so main reservoir air blows through 
rotary into main exhaust port. The preliminary exhaust 
and emergency exhaust ports are closed as well as the feed 
port / leading to the excess valve or feed valve. 

When on the next position, called running position 
because it is the proper position when train is running 
with brakes released, the direct supply port is covered so 
that main reservoir air can not get into brake pipe direct, 
the supply port e is also covered so no main reservoir air 
can pass through into chmber D. The feed port / is 
opened and main reservoir air must then pass through this 
port and go past the excess valve or feed to get into the 
brake pipe. Brake pipe air can pass through the cavity 
c under rotary and go through port g into chamber D and 
equalize the pressure on both sides of the equalizing 
piston. The small warning port is covered. On lap posi- 




tion all ports are closed so no air can pass under or 
through the rotary. On service application position the 
preliminary exhaust port h is opened so air flows out of 
chamber D ; this is done by a movement of the rotary, the 
equalizing piston opens the brake pipe exhaust port auto- 
matically. All other ports are closed. 

On emergency position the direct application port is 
opened, allowing the air in the brake pipe to pass directly 



$£flV/C£ /?FP/./C/?T/OA/ /=>0<S/T/OA/. 




LEAKS 69 

to the atmosphere through the cavity under the rotary. 
As this is the largest port in the brake valve, if it is opened 
wide the air in the brake pipe will escape suddenly. 

The preliminary exhaust port is left open, all other 
ports are closed. The port from brake valve to brake 
valve reservoir is open at all times. 

21. Q. Do leaks in the brake valve interfere with its 
work? 

A. Yes; if there is a leak under the rotary valve from 
the main reservoir to brake pipe, the brake pipe pressure 
will raise so that the brake will release when valve is on 
lap. A leak from brake pipe under rotary valve, or 
through brake pipe discharge valve to atmosphere, or a 
leak between equalizing reservoir and brake valve when 
valve is on lap, will set the brake tighter than you want 
it. If it leaks through gasket from main reservoir to 
cavity over equalizing piston 47 in F-6 valve, or past 
gasket 18 in the H-type valve, brake cannot be set in 
service application, as air will flow into chamber D from 
main reservoir as fast as it flows out of preliminary 
exhaust. Using the brake valve on emergency habitually 
will tend to cut the rotary and seat quicker, as it brings 
sand and scales of iron rust up from the brake pipe on 
the seat, which the service application will not do. If 
the brake valve is fastened close to the boiler head so it 
gets very hot, the leather gaskets get burned and crack 
so they leak badly. A bad leak past the equalizing piston 
will cause engine brakes to release when set with a light 
direct application. This is because air leaks from equal- 
izing reservoir past piston and raises brake pipe pressure 
in the short brake pipe on engine and tender. This leak 
will also prevent the equalizing piston raising -when mak- 
ing a service reduction if the air can come past the piston 
into chamber D as fast as it is discharged through pre- 
liminary exhaust port. It also makes the brake pipe re- 
duction less than the gage at first shows, on a long train. 

22. Q. What is the effect if equalizing reservoir pipe 
is broken so a blind joint has to be made? 



70 BROKEN EQUALIZING RESERVOIR PIPE 

A. The brake cannot be set with a gradual application 
in service position ; there is so little air above the equal- 
izing piston, it escapes out of preliminary exhaust so 
quickly that the pressure above piston is reduced more 
than twenty pounds, equalizing piston stays up and the 
brake works with full application; some times emergency 
with a very short train. 

23. Q. What should you do in such a case? 

A. If joints cannot be made so as to use equalizing 
reservoir again, a blind joint should be made at its con- 
nection with brake valve; the elbow in brake pipe exhaust 
should be plugged and valve used with direct application 
port, taking care to make a gradual reduction so brake 
will not go on with emergency, and closing valve slowly 
so the brakes on head end will not be kicked off. The 
elbow has a thread cut in it for plugging; if it is not 
threaded take it out and plug the hole with the plug in 
the equalizing reservoir. A Y% plug is used with, the 
type H valve. 

24. Q. With the equalizing discharge valve, why does 
the air blow out of the brake pipe exhaust when brake is 
released, if working brake on engine and tender only? 

A. Because the brake pipe is charged up through a 
large hole in rotary valve; the cavity over equalizing 
piston and brake valve reservoir is charged from the main 
reservoir through the small supply port e for preliminary 
exhaust, and by equalizing port g. If the brake pipe is 
short, it will charge up to a full pressure quicker than the 
space above piston; brake pipe pressure will then raise 
piston and discharge valve, allowing air to blow out of 
brake pipe exhaust elbow for a second or two. There 
is no flash of air from the type H brake valve when 
coupled to any cars. A short flash of air comes from the 
H type when additional cars are cut in, if the H-5 valve 
is on lap, the H-6 on running position, as air will blow 
out of the application chamber caused by the brake pipe 
reduction. 



BRAKE PIPE EXHAUST 71 

25. Q. Can this action of the valve be of advantage 
to you? 

A. Yes ; if you hear this escape of air from brake pipe 
exhaust when releasing brake on a train, it is a sign of a 
short brake pipe ; and is a notice to the engineer that an 
angle cock at the head end of train is closed, or something 
has got into the brake pipe and stopped it up. You should 
see at once if an angle cock is not shut by some mistake 
or malicious intent. Check chains swinging against the 
handle will close it. 

26. Q. Does the amount of air which blows out of 
brake pipe exhaust when setting the brake with a service 
application give you any idea of the number of cars in 
your train working air? 

A. Yes, with engine and tender only, the brake pipe 
exhaust does not blow much, if any, longer than pre- 
liminary exhaust. With a long train it takes some seconds 
for the brake pipe pressure to be reduced and equalize its 
whole length. You can, after some practice, tell whether 
you have a long or short train working air by listening to 
the amount of air escaping from barke pipe exhaust. This 
test shows the length of brake pipe cut in and filled with 
air, not the number of brakes that set. It takes consider- 
able practice to tell how many cars are coupled on. By 
this test it gives the number of car lengths of brake pipe 
in use ; if the triple is cut out on any car it gives you no 
notice. When some of the cars are cut out by closing 
angle cocks, a less amount of air will come out than with 
all of them. It is important to know this, as some of the 
angle cocks may be closed, thus cutting off all the cars 
behind the closed one. In making a test for the length of 
brake pipe connected to the brake valve, reduce your brake 
valve pressure exactly five pounds by the gage and then 
note the amount of air coming out of the brake pipe ex- 
haust. Always use the same amount of reduction as there 
is no sure way to compare the length of brake pipe exhaust 
for different trains unless the same brake valve reduction 
is used as a measure each time. A partly opened angle 



72 DOUBLE HEADING COCK 

cock can be detected by this test, for the air will flow with 
a strong, steady sound from the brake pipe ahead of the 
partly opened cock, while the air from the pipe behind it 
will string out longer and weaker than it should. Look 
out for this, as the brakes can all be set. but as the air 
equalizes very slowly into the rear cars some of the triples 
in rear cars are liable to stick. With a full train of quick- 
service triples considerable brake pipe air goes through 
these triples to the brake cylinder; so a less amount of air 
will come out of the brake valve from the brake pipe than 
with the older form of triples. 

27. Q. What is the stop cock under brake valve for? 
Will it assist you in locating leaks? How? 

A. To cut out the brake pipe from brake valve when 
double heading, so only one engineer can control all 
the brakes. For this purpose it is absolutely necesary. 
Yes, it will assist in locating leaks. When shut, after 
charging brake pipe and auxiliaries, if there is a leak in 
brake pipe, brake will set at once ; if the rotary leaks either 
into or our of the brake pipe, it will show it very soon, as 
there is so short a brake pipe to leak into or out of. A 
little observation will teach you many ways of using this 
cut-out cock in testing for leaks. With the H-5 valve 
and the distributing valve this stop cock controls the ex- 
haust from the distributing valve. 

28. Q. If you had an 1892 or an H-type valve and the 
brake would not go on in service application, nor the black 
hand fall, nor the brake pipe exhaust open, while air came 
readily from preliminary exhaust, what would be the 
matter ? 

A. I would look for a leak at the joint on lower gasket 
where a leak would allow air to get from main reservoir 
direct to cavity over equalizing piston No. 47. This would 
give main reservoir pressure to chamber D and show it on 
the black hand. A brake valve with this leak would show 
very little or no excess pressure. No ajr could come out of 
brake pipe exhaust, as the pressure could not be reduced 
over the piston so valve could be raised. To set the brake 



DISABLED BRAKE VALVE 73 

use direct application port, opening and closing it slowly. 

29. Q. If you had a continual blow at the brake pipe 
exhaust port of the brake pipe valve and could hold no air, 
where would the difficulty be apt to be found? 

A. Stuck or leaky equalizing piston, dirt on its valve 
seat, brake valve reservoir bleed cock open, or bad leak in 
pipe to brake valve reservoir or gage. Would put valve 
on lap, then on emergency for a moment and see if that 
would stop it, or close the stop cock under the valve and 
flash the valve to clean off the seat. 

30. Q. How should the brake valve handle be placed 
when running or standing with brake released, unless 
auxiliaries are being charged? Why? 

A. Always in running position. Because this is the 
only position in which you can carry excess pressure, 
which is needed to release brakes promptly. With 1892 
valve on full release the brake pipe pressure will run up as 
high as pump governor will allow; this high pressure is 
apt to slide the wheels. A small blow hole is put in the 
rotary valve to warn engineer that valve has been left 
in full release. All valves should have this warning port; 
if it gets stopped up, it is a sign that there is dirt on 
top of rotary valve,. which should be taken out and cleaned 
at once. When on running position the opening through 
brake valve from main reservoir to brake pipe is a smaller 
one than on full release. If the train breaks in two or 
conductor's valve is opened to stop the train in case of 
accident, the brakes will operate instantly as the brake pipe 
pressure can be reduced from the train faster than the 
running position feed port can supply it. If the valve is 
on full release the brakes will not set tight till the main 
reservoir pressure is also reduced. If necesary to hold 
engine brakes with the H-type valve after a release of 
train brakes, use holding position. 

31. Q. What are the essential differences between 
the 1892 model and the 1906 or H-5 brake valve? 

A. The H-5 brake valve has all the pipe connections 
made at the bottom section or pipe bracket, so the valve 







H/£ AUTOMATIC BRAKE VALVE 



H-5 BRAKE VALVE 75 

can be removed from the engine without disturbing any 
pipe joints. The feed valve is located on a pipe between 
the main reservoir and brake valve. The brake valve 
receives main reservoir air direct through one pipe. This 
air comes on top of the rotary. Air at a reduced pressure 
comes through the feed valve and another pipe; coming 
under the rotary at port d. The preliminary e and emer- 
gency exhaust x is through the center of the rotary o into 
the cavity EX in section 3 of the valve and thence to the 
atmosphere. The brake pipe exhaust is at the bottom and 
in the center of the valve. This valve is intended to be 
used in connection with an independent brake valve and 
the distributing valve for the locomotive brake and has 
two pipe connections for this purpose. In the rotary valve 
seat there is a port / that connects with the pipe leading 
from the application chamber of the distributing valve 
through the independent brake valve. When the rotary 
is in running position port h in the rotary registers with /, 
if the independent valve is also in running position, the 
locomotive brake will be released. 

There is another position of the H-5 valve, called hold- 
ing position, located between running and lap, in which 
port h does not register with port I, but air coming through 
the feed valve can pass out of d through f in the face of 
the rotary into b, thence through a cored out passage to 
c and the brake pipe leading to the train. With the H-5 
valve in holding position the train brake will be re- 
leased and the locomotive brake held set. This port / is 
also lapped in full release, so that the train brake can be 
released and at the same time the engine brake be held 
set if required; this will hold the slack back in the head 
end of the train and make it safe to release the train brake 
at slow speeds, and not break in two. Another port u in 
the rotary seat connects with the double heading pipe, port 
h registers with u in lap position. This pipe leads from 
the exhaust port of the distributing valve and is only used 
on the following engine of a double header. When the 



76 H-5 BRAKE VALVE 

double header cut out cock under the brake valve is closed 
this pipe connection through the cock is open. 

In the emergency position of the rotary, port / in the 
seat registers with port g through the groove n in the 
face of the rotary so that in emergency position air from 
the brake valve reservoir can flow into application chamber 
of distributing valve and apply the engine brake with 
greater force. Port p connects with the excess pressure 
head of the pump governor, when the rotary is in full re- 
lease, running or holding positions; main reservoir air 
can pass through port ^ in the rotary and the small groove 
in its face and enter port p, thus controlling the excess 
presure head of the governor in these positions. In full 
release main reservoir air from port s flows through the 
warning port r into EX and gives the warning that the 
valve is in full release position. In service position port h 
in the rotary registers with e in the seat, air from cham- 
ber D flows into o and EX, all other ports in the seat 
are closed. The action of the equalizing piston 15 has 
already been, described. Cavity k in the face of the rotary 
connects ports g and c in runing and holding positions, 
so that brake pipe and chamber D charge up alike in these 
positions and there is no flash of air from the brake pipe 
exhaust when releasing brakes with a short train. 

Plug 29 can be taken out and some good oil poured 
in the cavity around the lower edge of the rotary to lubri- 
cate it. Spring 30 holds the rotary key 7 up against gasket 
8 when there is no air pressure to do this, in full release 
position main reservoii air passes thro ugh ports a in the 
rotary and directly into port b and the brake pipe, and port 
quickly. In running and holding positions cavity f in the 
face of the rotary connects ports d and b so the air that 
has been reduced in pressure at the feed valve can flow 
into the brake pipe and charge it up to the pressure that 
the feed valve closes it, and no higher. To take the H-5 
valve off its pipe bracket take out the through bolts. To 
take the valve apart take out the tap bolts that hold the 
valve sections together. 



INDEPENDENT BRAKE VALVE 77 

32. Q. Describe the independent brake valve. 

A. This valve is used in connection with the distribut- 
ing valve and allows air to flow into or out of the applica- 
tion chamber, and thus operate the supply valve piston, 
that in turn operates the valves which admit main reser- 
voir air to the brake cylinder to set the engine brake or 
exhausts the cylinder air to release it. It does not admit 
main reservoir air direct to the brake cylinder as the 
Straight Air brake valve does. It has four positions, 
release, running, lap and service, that come the same as on 
the automatic brake valve. A stiff spring 9, in the top of 
the valve body 3 returns the handle from release to run- 
ning position as soon as the engineer removes his hand. 

In running position port d from the distributing valve 
is connected through port f in the rotary 5 with port c 
leading to the automatic valve, so that air can flow from 
the application chamber through the independent valve to 
the automatic brake valve, and this valve should always 
be in running position when the automatic valve is to 
operate the engine brake. In release position cavity g in 
the face of the rotary 5 connects port d with the exhaust 
port h in the center of the seat, so that the application 
chamber air can pass to the atmosphere without regard to 
the position of the automatic brake valve and release the 
engine brake independently of the train brake. In service 
position cavity e in the rotary connects the supply port b 
with d so that main reservoir air reduced to 45 pounds can 
flow direct to the application chamber and operate the dis- 
tributing valve supply piston; this position applies the 
engine brake independently. Lap position blanks all ports 
and is to be used only when making a graduated applica- 
tion or release of the engine brake or when trying to 
prevent the release of the engine brake by the automatic 
valve, or the passage of air from the brake valve reser- 
voir through the automatic valve in the emergency posi- 
tion to the application chamber. Leaving the independent 
valve in lap position when operating the automatic valve 



78 



INDEPENDENT BRAKE VALVE 



is liable to cause trouble. This valve does not affect the 
operation of the train brake in any way and is to be used 



automatic e**K£ vAive 



Distributing VACVt 

\ St*VICl, 




SEST) 



INTERIOR VIEWS OF THE INDEPEND 
-ENT BRAKE VALVE 

when operating the engine brake while switching cars, 
or independently at any time. Its supply of air comes 
from the main reservoir through a reducing valve set at 
45 pounds. The arrangement of these valves is shown in 
the page illustration and they are part of the ET locomo- 
tive brake equipment. The location of each valve in this 
type of brake is plainly shown, so no description is given. 

33. Q. Describe the distributing valve in its construc- 
tion and operation. 

A. The distributing valve is shown separately and 
attached to its double-chambered reservoir. The pressure 



80 



THE DISTRIBUTING VALVE 



chamber represents an auxiliary reservoir and the applica- 
tion chamber the brake cylinder as regards the equaliza- 
tion when the air passes to the application chamber; this 
comparison is for explanatory purposes only. There are 
five pipe connections, only two of which show on the ex- 




fnpcTAP 

TO WMEP6NOCNT 
'ffMlX VAUVC 



posed side of the reservoir. On the next page is shown a 
diagrammatic view of the valve and reservoir, in which 
the valve is shown much larger in proportion to the size 



22 




m 



RELEASE, AUTOMATIC OR 
INDEPENDENT 



82 THE DISTRIBUTING VALVE 

of the reservoir than it really is. We will use capital let- 
ters as abbreviations for the names of the five pipe connec- 
tions made to the reservoir and from there to the various 
parts of the valve. In the diagrammatic view slide valve 
31 and graduating valve 28 are shown both above and 
below the piston stem 26, so the ports that are beside each 
other can be seen. Air from main reservoir enters at sup- 
ply, passes through port a up and around application valve 
5; also down to seat of slide valve 31 and through 
port n to the pressure chamber when valve 31 is in 
emergency position. Air from the brake pipe enters at 
BP and is on the outside of equalizing piston 26. When 
this piston is in release, as shown, brake pipe air can pass 
around the piston through the feed port into the pressure 
chamber. When thte brake pipe pressure is reduced piston 
26 moves back towards the reducing train pipe pressure, 
bringing first graduating valve 28 and then moving slide 
valve 31 as soon as the lost motion between the shoulders 
on piston stem and valve 31 is taken up. This admits 
air from the pressure chamber to the application 
chamber through ports o and h, and in this respect is 
exactly like a triple valve when feeding air from the 
auxiliary to the brake cylinder. With a partial application 
of the automatic brake equalizing piston 26 and its 
valves reduces the pressure in the pressure chamber by 
allowing air to pass into the application chamber till the 
pressure chamber is a trifle lower than the brake pipe 
when piston 26 moves back and laps graduating valve 28. 
This movement has been fully explained in connection 
with the triple valve. 

At the same time that air flows into the application 
chamber, it also flows up through port h into the space g 
behind the application piston 10. This moves application 
valve 5 and as soon as the lost motion is taken up, 
exhaust valve 16 covers the exhaust ports e and d. 
Valve 5 next opens the supply port from a into b and c, 
so main reservoir air can flow to the brake cylinder at BC 
and apply brake. We will suppose a 7-pound reduction 



OPERATION OF DISTRIBUTING VALVE 83 

is made in the brake pipe. As soon as it is felt on the 
piston 26 at p it will move towards BP, open valves 28 
and 31 closing exhaust port k Air will flow into the 
application chamber and cavity g till the pressure cham- 
ber is also reduced 7 pounds, when piston 26 will move 
back and lap valve 28 over the port in valve 31. Air 
pressure in g will then move piston 10 and its valves 
5 and 16, "closing the exhaust ports c and d and opening 
supply port from a to c. To open port from a the gradu- 
ating stem 19 must be moved back against the tension of 
its spring 20, when the stem 19 meets cap nut 22. As 
soon as the presure in b and the engine brake cylinders 
is equal to that in that in g on the other side of piston 10, 
spring 20 and the stem 19 will move piston 10 and valve 5 
back to lap, but does not move valve 16 to open the ex- 
haust. This applies the brake and holds it applied as long 
pressure remains in g and h. If leaks in the brake cylin- 
der packing or piping reduce the pressure in b, piston 10 
will move towards this lecreasing pressure and open the 
supply port till the pressure in the cylinder again equals 
that in g, when piston 10 will lap valve 5. When the air in 
the application chamber is either wholly or partly ex- 
hausted to the atmosphere, piston 10 will be moved back 
towards g by the brake cylinder pressure and either wholly 
or partly exhaust the air from the cylinder. 

In the independent application and release of the 
brake through the distributing valve the lower or equal- 
izing piston 26 and its valves do not move. The air is fed 
into and out of the application chamber and chamber g 
by the independent brake valve at the pipe connection AC. 
This air comes from the main reservoir and is reduced to 
45 pounds presure befoure passing through the independent 
brake valve. When the independent valve is in service 
position air flows in at AC till the pressure in the appli- 
cation chamber and g is enough to apply the brake the 
desired amount. A partial or full application can be made 
depending on how much air is admitted through the brake 
valve, and a partial or full release by lapping the brake 



84 OPERATION OF DISTRIBUTING VALVE 

valve before all the air has escaped. To prevent the air 
passing out the exhaust port k of valve 31 when in re- 
lease position port i is piped at DH to the double heading 
cock in the brake pipe under the automatic brake valve. 
When this cock is open for the brake pipe, as it should be 
when the automatic brake is being operated from that 
engine, the pipe leading from the exhaust port k is closed 
so no air can escape through valve 31 when in release 
position. But if this engine is not operating the train 
brake in a double header the exhaust port k is open 
through a pipe from DH through the cut-out cock and a 
port in the H-5 automatic brake valve when the rotary 
is in lap position. 

There is a cut-out cock in the brake pipe connection 
before reaching BP to cut out the distributing valve from 
operating automatically when necessary. Closing this cut- 
out cock does not prevent the brake being operated by 
the independent brake valve. 

When the automatic brake valve is in the emergency 
position air from the brake valve reservoir can flow 
through a port in the H-5 valve, then through the inde- 
pendent valve — if it is in running position — into the 
application chamber and g, so that the engine brake can 
be applied in that position of the automatic valve, even 
if cut out from the brake pipe. This is a feature of the 
H-5 only. 

When piston 26 is moved its full travel to the emer- 
gency application position so it rests against gasket 25 in 
cap 23, ports n in the bushing and m in valve 31 will be 
open to each other so main reservoir air can flow slowly 
through the small port n into the pressure chamber and 
increase the pressure there. At the same time port / is 
open to the safety valve 34 and it will reduce the pressure 
there to about 60 pounds. This feature is intended to 
operate the brake the same as the high speed reducing 
valve. In the No. 5 distributing valve (the one here 
described), port / is only open to the pressure chamber 




<*.-SAFETY VALVE ' 



No. 6 E. T. EQUIPMENT 85 

and port h in application position; being 
closed in release and lap positions of valve 
28 and 31. For this reason, when using the 
independent brake valve only with the equal- 
izing piston 26 in release or lap the safety 
valve 34 will not reduce the pressure in the 
application chamber should the reducing valve 
for the independant valve be out of order and 
allowing too high a pressure. This safety 
valve is set at 53 pounds, and will blow down 
to that with an automatic service application. 
34. Q. Are there any differences between the No. 

5 ET equipment and the later design, No. 6? Describe 
them. 

A. The No. 6 ET equipment was designed later 
than the No. 5 just described, there are several differences 
between the No. 6 and any previous type that enable No. 

6 to get the same results easier and have many added 
advantages. 

The release pipe between the automatic brake valve 
and the independent valve goes direct and not through 
the double heading cock, the double heading cock of the 
H-6 is an ordinary stock-cock the same as used with the 
F-6 valve. In double-heading the normal position of the 
H-6 valve is running instead of lap as with the H-5. The 
release pipe from the distributing valve comes from the 
application cylinder with No. 5 and from the exhaust of 
equalizing slide valve 31 with No. 6, so that valve 31 
must be in release position to release the distributing 
valve through the H-6 valve. With No. 5, air could 
come out of the application cylinder and chamber through 
the two brake valves in running position regardless of the 
position of slide valve "31. The application cylinder pipe 
of No. 6 goes direct to the independent valve as before, 
a Tee connection is put in leading to the H-6 maintaining 
port. In No. 5 this port was in the distributing valve. 

In an emergency application with the No. 6 slide valve 
31 moves quickly and laps the port into the application 



No. 6 DISTRIBUTING VALVE 87 

chamber so the pressure chamber equalizes with the 
application cylinder only, at very nearly the amount of 
pressure in the chamber at first, about 65 out of 70 
pounds. In a service application the port to the applica- 
tion chamber is held open so the pressure chamber equal- 
izes with the combined volume of the application chamber 
and cylinder at 50 out of 70 pounds. 

The positions of the two smaller pipes at the bottom 
of the distributing valve are reversed in No. 6 from that 
in No. 5. The application cylinder pipe is the lower one 
in No. 5 it is the upper one in No. 6 ; the lower one in 
No. 6 connects with the exhaust of valve 31. In No. 5 
the double heading pipe that did this work was the upper 
one. 

There is a special cap for the cylinder of piston 26, 
containing a quick-action valve to vent brake pipe air 
to the brake cylinders and a rubber seated check to hold 
it there, this will hurry up the quick-action on the train 
as a quick-action triple on a tender will do. 

There is only one position of slide valve 31 of the No. 
6 in which safety valve 43 is not connected to the applica- 
tion cylinder, automatic lap, in all other positions the 
safety valve will take care of the over pressure. 

A careful study of the explanation of the No. 5 will 
assist in understanding the No. 6, the points that are 
common to both valves need not be explained again. 

35. Q. Describe the H-6 brake valve and its operation. 

A. The H-6 valve is similar in outside shape to the 
H-5 ; there are differences in the air ports and cavities ; 
using the cut of the rotary and its seat to trace the course 
of the air in different positions will give a good idea of 
the work of the valve. It has six positions; full release, 
running, holding, lap, service application and emergency. 
Main reservoir air comes in over the rotary valve at 
MR; feed valve air at FV under the rotary at port d; 
b is the supply port through the seat for the brake pipe 
and c the emergency exhaust from the brake pipe, o is 



88 No. 6 DISTRIBUTING VALVE 

the exhaust opening and x the emergency exhaust passage 
in the rotary; / connects d and b in running position. 

In full release, port a through the rotary registers 
with port b, the brake pipe; so main reservoir air at full 
pressure goes directly to the brake pipe in this position; 
/ in the rotary registers with g in the seat, so chamber 
D charges with main reservoir air direct in this position; 
Cavity f in the face of the rotary connects port d with 
warning port r in the seat and allows a small amount of 
feed valve air to escape to the atmosphere, serving two 
purposes warning the engineer to move the valve from 
full release and giving an idea of how sensitive the feed 
valve is. Port s through the rotary has a small groove 
at the face, this connects with port p in the seat allowing 
main reservoir air to flow to the lower connection of the 
excess head of the pump governor in full release, running 
and holding positions. 

In running position port a through the rotary is closed 
at its lower end so no main reservoir air can go directly 
to tne brake pipe, cavity f connects d and b so air from 
the feed valve can flow to the brake pipe; cavity k con- 
nects ports c and g, the brake pipe and chamber D can 
now equalize. Port ^ still registers with port p leading to 
the governor, h in the rotary registers with / in the , seat 
that connects with the release pipe and allows air ex- 
hausted through valve 31 from the application cylinder 
and chamber to escape and release the locomotive brake. 

When an empty train is being charged, as long as the 
brake valve is in full release the pump will run at speed, 
but when the valve is moved to running position the 
action of the S-F pump governor is sometimes puzzling. 
As one side of this governor is operated by the excess 
pressure if the feed valve cannot pass the air to the 
brake pipe as fast as the pump supplies it, the excess 
will build up enough between the main reservoir and 
brake pipe pressures to have the governor stop the pump. 
In such a case move brake valve to full release and leave 




MAIN RCSEKVt/R 



CdOajjzing Rcsoivem. 



—THE H-6 AUTOMATIC BRAKE VALVE 

it there till the brake pipe pressure is close to the 
standard. 

Holding position leaves all the ports that were open 



90 H-6 BRAKE VALVE POSITION 

in running position still open, except I, that is now lapped 
instead of being open to h, the distributing valve cannot 
release through that port. This position will release and 
charge up all the automatic parts of the brake on train 
and engine, but hold the engine brake set. 

On lap position all ports in the rotary and its seat 
are lapped; there is no passage for air in any direction 
through the ports. 

On service position all ports are lapped, except the 
preliminary exhaust port e, this registers with h in the 
rotary, the air in chamber D will now pass out slowly, 
brake pipe air will raise equalizing piston 15 and its 
valve and discharge brake pipe air to the atmosphere. 

When the H-6 ,is placed in emergency position, port 
x in the rotary registers with c in the seat, making a 
large opening from brake pipe to atmosphere through o 
in the rotary and EX in the seat. The sudden reduction 
in brake pipe pressure starts the quick-action in the train 
brakes and applies all of them in the shortest space of 
time. Main reservoir air is now passing through port / 
in the rotary, thence through a small port into cavity k 
and small port n into port u in the seat, and thence 
through the Tee connection into the application cylinder; 
this maintains the pressure in this cylinder up to when 
the safety valve controls it. Port t in the rotary registers 
with equalizing port g, air in chamber D will pass out to 
the atmosphere instead of going to the application chamber 
as it does with H-5. 

36. Q. Describe the S-6 independent brake valve. 

A. The independent brake valve S-6 has five posi- 
tions: Release, Running, Lap, Slow Application and Quick 
Application. A return spring 6, coiled inside the top of 
the valve will return the handle 15 from release to run- 
ning, and from quick application to slow application; the 
engineer will feel the resistance of this spring when mov- 
ing the rotary to its full travel, either way. The warning 
port / is provided to warn the engineer in case this spring 
is broken. Air from the reducing valve at 45 pounds 



S-6 INDEPENDENT VALVE 



91 




Rotary Valve 
THE S=6 INDEPENDENT BRAKE VALVE 

pressure comes in at port b and on top of rotary through 
port e. Port a leads air through the release pipe IV from 
the distributing valve exhaust of slide valve 31; port c 
connects with the release pipe to H-6 at port e ; ports 
a and c are connected by groove / in the rotary 9 when 
in running position; with both valves in running position, 
air exhausted by slide valve 31 can pass through the 
S-6 and escape at the H-6 valve. Port d leads to the 
application cylinder pipe II, in independent application 
air passes in through this port and pipe to application 
cylinder; in independent release air passes out this way. 
A Tee in this pipe leads to the maintaining port u in the 



92 NO. 6 DISTRIBUTING VALVE 

H-6 rotary, h is the exhaust port, exhaust cavity g in 
rotary 9 always registers with it. k is the warning port, I 
is the warning port in the rotary, open in release. A 
small port m connects with groove e and registers with d 
in slow application, passing air slowly; in quick applica- 
tion position the larger groove e registers with d and 
passes a large amount of air to the application cylinder, 
setting the brake quickly. The latter part of answer to 
Q. 32 gives directions for operating this valve. 

37. Q. Explain the operation of the No. 6 Distribut- 
ing Valve. 

A. The diagrammatic view of the No. 6 distributing 
valve gives a good idea of the application portion at the 
top of the cut; the equalizing portion is in the middle; 
the double chambered reservoir is at the bottom; for 
the reference letters and numbers, look at the next 
diagrammatic cut. Main reservoir air comes into the 
application portion only, a pipe leads to the brake cylin- 
ders. The movement of the application piston and its 
two valves admits main reservoir air to the brake cylin- 
ders or exhausts cylinder air to the atmosphere. Admit- 
ting air at a pressure into the application cylinder will 
move piston 10 and its valves to the right, first closing 
exhaust ports under valve 16, next opening air port under 
. valve 5, so main reservoir air can flow to the cylinders. 
If we have put 10 pounds pressure against piston 10 and 
opened the air port, air will flow in till the brake cylinder 
pressure builds up to 10 pounds ; piston 10 will then b(. 
balanced between the two pressures; a graduating stem 
19, and its spring 20, in the end of the piston stem will 
move the piston and valve 5 back to lap. Increase the 
pressure in application cylinder, piston 10 and valve fi 
will move to admit more air, when pressures are balanced; 
valve 5 will close, thus the pressure can be built up in the 
brake cylinder by admitting air to the application cylinder. 
To release the brake, allow part or all of the application 
cylinder air to escape; piston 10 will be moved to the 
left by brake cylinder pressure, opening the ports under 



DIAGRAMMATIC DISTRIBUTING VALVE 



93 



valve 16 the brake will then be all or partly released, de- 
pending on the pressure left in the application cylinder. 
If leaks in the brake cylinder reduce pressure there, piston 



TO MAIN RESERVOIR. 



TO INDEPENDENT A 
AUTOMATIC BRAKE VALVES. 



TO INDEPENDENT BRAKE VALVE. 




APPLICATION 
CHAMBER. 






PRESSURE CHAMBER. 



DIAGRAMMATIC VIEW OF THE ESSENTIAL 
PARTS OF THE DISTRIBUTING VALVE, AND 
DOUBLE-CHAMBER RESERVOIR. 



94 



OPERATION OF DISTRIBUTING VALVE 



10 will move to the right, open supply valve 5 and build 
the brake pressure up to equal that in the application 
cylinder; leaks out of the application cylinder or its 
piping will tend to release the brake. There are two 
ways of letting pressure into and out of the application 
cylinder ; one by way of the independent valve and H-6 
valve, the other is by the operation of the equalizing 
portion of the distributing; this is shown clearly in the 
diagrammatic view of automatic service. The brake pipe 



MR 




AUTOMATIC SERVICE 



OPERATION OF THE DISTRIBUTING VALVE 95 

connection supplies brake pipe air to this portion the same 
as to a triple; air feeds around piston 26, through feed 
port r charging up the space around valve 31; passes 
through port o into the pressure chamber till the pressure 
there equalizes with the brake pipe. To make an auto- 
matic service application of the distributing valve, the 
brake pipe pressure is reduced, piston 26 at once moves 
to the right, a part of its full travel to the position shown 
in the view; first moving graduating valve 28 to open 
port z and closing feed port v. Slide valve 31 is next 
moved to register ports z and h, air from the pressure 
chamber flows through z, h, and w into both application 
chamber and application cylinder g, building up a press- 
ure against piston 10. Safety valve / is now connected 
through ports r and s with h; this allows application 
cylinder air access to the safety valve. Suppose we make 
a 7-pound reduction in brake pipe and move piston 26 and its 
valves, as soon as the air in the pressure chamber and on that 
side of piston 26 is reduced, a little more than 7 pounds by 
going into the pressure chamber and g; piston 26 will 
move towards this, decreasing pressure, covering port z 
with valve 28; no more air will pass out of the pressure 
into the application chamber and g; the action in this 
respect is like a triple valve feeding air from an auxiliary 
to a brake cylinder, described on page 8. 

Another brake pipe reduction will send more air from 
the pressure to the application chamber and g 3 till the 
pressures in these two chambers are equalized, after that 
the pressure in g cannot rise any higher with an auto- 
matic application. A pressure built up in g will operate 
piston 10 and its valves to send main reservoir air to the 
brake cylinders; exhausting air from g will release the 
brake. To release the engine brake automatically, re- 
charge the brake pipe till its pressure will move piston 
26 and valve 31; to release position air from g and the 
application chamber will then pass out under valve 31 
through pipe IV to the brake valves, with both of them 
in running position this air can get to the atmosphere, 



96 



OPERATION OF THE DISTRIBUTING VALVE 



piston 10 will then open exhaust valve 16 and release 
the brake. 

In the independent application and release of the brake 
through the distributing valve, lower piston 26 and its 
valves do not move, but remain in the position they have 
been placed in by the automatic brake valve, changes in 
brake pipe and pressure chamber pressures move this 
piston. 



MR 




EMERGENCY POSITION OF No. 6 DISTRIB- 
UTING VALVE WITH QUICK-ACTION CAP. 



QUICK-ACTION DISTRIBUTING VALVE 97 

The No. 6 valve is provided with a quick-action cap 
47, that can be used in place of the plain cylinder cap 
23 on large passenger engines or those used* in double- 
heading regularly. This cap 47 contains an emergency 
valve 48 attached to the graduating stem 50, so they move 
together and a rubber seated check 53, and its spring 54, 
that opens to admit brake pipe air to passage m, leading 
to the brake cylinder pipe at c. An over-reduction of 
brake pipe air in service application will move stem 50 
and valve 48 to open port j, but in this application brake 
cylinder has equalized with brake pipe and no air will 
pass the check-valve 53. When a sudden and heavy 
reduction in brake pipe pressure is made as the first 
reduction, piston 26 moves its full travel, at once push- 
ing stem 50 over against the resistance of spring 55, 
moving valve 48 to uncover port /; this makes a sudden 
reduction of brake pipe air that will insure the quick- 
action of triples on the train in the same way a quick- 
action triple on the tender will. When the brake pipe 
air equalizes with the brake cylinder, check-valve 53 
closes so air can not pass back from the cylinders. Air 
from the pressure chamber flashes into the application 
cylinder and operates piston 10 to set the brake when 
this sudden reduction operates piston 26. Valve 31 passes 
over port w so quickly that very little air gets into applica- 
tion chamber, pressure chamber air equalizes with applica- 
tion cylinder g only at very near its original pressure, 
about 65 out of 70 pounds and sets the brake at that 
pressure. 

If the H-6 valve is left in emergency position its 
maintaining port u will pass main reservoir air through 
pipe II and build up the pressure in g till the safety valve 
set at 68 pounds can control it. 

In High Speed Brake service with the feed valve 
carrying 110 pounds instead of 70, the main reservoir 
pressure is usually 130 to 140 pounds ; this pressure at the 
H-6 valve will force more air through port w and raise 
the pressure in g to about 93 pounds. The small opening 



98 . DOUBLE HEADING 

between q and r in slide valve 31 is just enough larger 
than port w so the air can be reduced to 75 pounds by 
the safety valve; this higher pressure gives a quicker 
stop in High Speed service. When the H-6 brake valve 
is put in release position, after an emergency stop, and 
the brake pipe pressure is built up enough to move piston 
26 to release, the air in the application cylinder can then 
equalize into the application chamber at about 15 pounds; 
this will hold the locomotive brake set at that pressure 
till the H-6 is moved to running position, it will then 
fully release. 

In double heading the cock under the H-6 brake valve 
must be closed on the following engines to give the lead- 
ing engineer control of the brakes and the H-6 and S-6 
valves carried in running position; this will leave the 
exhaust port of valve 31 open to the atmosphere so the 
leading engineer can use the distributing valves on the 
following engines, the same as triple valves on the train. 
If necessary to release the engine brake on the following 
engines, it should be done with the independent brake 
valve without moving the H-6 from running position. 
When backing up a train that is to be controlled with a 
tail hose, the H-6 should be carried in running position, 
unless the rules of the Company require another position. 





COMBINED AIR STRAINER AND CHECK 
VALVE 

There is a connection from the brake pipe to the main 
reservoir pipe with a stop-cock to keep it cut out when 
not needed, and a strainer check valve to prevent air 
from coming back from the reservoir; this for use on 



DEAD ENGINE CONNECTION 99 

a dead engine when drawn in a train. This connection 
will furnish a supply of air to operate the E. T. brake ; 
the check valve is held down by a 20 pound spring, with 
70 pounds in the brake pipe there will me 50 in the main 
reservoir. A choke in the check case prevents air flowing 
out of the brake pipe fast enough to affect the brakes. 
The same type of strainer check without a spring is used 
between the 45-pound reducing valve and the signal 
system. The piping diagram shows the location of these 
strainer checks. 

When making a "two-application" stop with a 
passenger train and ready to make the first release; go 
to release position just long enough to move all the 
triples, then to running for an instant to allow the engine 
brake to release; the engineer's judgment must decide 
how long; you can then come to lap or service to make 
the second application; unless you stop an instant on run- 
ning the engine brake will remain full set. 

When operating the locomotive brake separately from 
the cars, use the independent valve, leaving the H-6 in 
running position. A partial or full application can be 
made by admitting a little or much air, and a partial re- 
lease by lapping the independent valve before all the 
air has escaped from the distributing valve. This valve 
can be used to bunch or hold the slack as well as to 
hold the engine brake set when standing at a water plug 
or on a grade. 

To cut out the brake pipe from the distributing valve 
there is a stop-cock in the branch pipe, and to cut out the 
driver or tender brake cylinders when disabled, there are 
cocks in the proper pipes. A choke fitting near the hose 
connection to the tender brake will hold the driver brakes 
set if the hose bursts or is uncoupled, as the distributing 
valve can feed air in faster than it can get through the 
choke. The choke is large enough to allow the tender 
brake to set and release without delay. 

The E. T. equipment must be kept clean and all the 
pipe joints and gaskets air tight if it is to operate prop- 



100 E T BRAKE DEFECTS 

erly. Grit or scales from the inside of the air pipes will 
cut the seats of the valves so they will leak, and leaks 
are the puzzle of this brake. Look out for leaks across 
the gasket between the distributing valve and its reservoir, 
as they occur there often. To locate leaks to the 
atmosphere use soapsuds at the suspected joint. To locate 
the leaks into the piping from the valves, open the pipe 
joints at the unions between the valves, air will come 
out from the pipe connected to the defective valve. You 
can then follow it up to the source of the leak. In case 
of broken pipes when out on the road, if you understand 
the operation of the valve there need be no trouble in 
understanding what to do and whether the brake can be 
still operated. If you will remember that the distributing 
valve depends on the pressure of air in the application 
chamber to open and close the valves that control the 
passage to and from the brake cylinder it will make the 
operation of this valve clear to you. When air gets into 
this chamber, whether from a leak through either brake 
valve, the slide valve 31 or the gaskets, it will raise the 
pressure there and apply the engine brake. Or, if the air 
can pass out of this chamber either the regular way 
through the brake valves or leaks in the pipe connections 
•the engine brake will release. First study out how the 
air gets into and out of this chamber and it will clear up 
many things that otherwise would puzzle you. 

There are several forms of the distributing valve in 
service, with some differences in their construction and 
operation, and it is likely that other changes will be made 
in the valve from time to time. 

38. Q. Describe the Combined Automatic and Straight 
Air Engine and Tender brake. 

A. This brake valve contains two check valves, 8 and 
9 — see Figures 1 and 2 — to admit air from the main reser- 
voir to the brake cylinders and 9 to exhaust the air from 
the cylinders to the atmosphere. These valves are moved 
away from their seats alternately by the shaft 2, which 
when revolved to the right, forces valve 8 off its seat 



STRAIGHT AIR BRAKE 



101 



against the pressure of the main reservoir air in a and tne 
spring 11; when revolved to the left forces the exhaust 
valve 9 off its seat against the pressure of the spring 10 
and the brake cylinder air. To apply the brake the handle 
4 is moved to the right. With valve 8 moved down off its 
seat, main reservoir air in a passes through b, b 1 and b- 
— see Fig. 3 — and out at x — see Fig. 2 — through the pip- 
ing leading to the Double Check valves and cylinders. 
Exhaust valve 9 at this time is on its seat as shown in 
Fig. 2, so that no air can pass out through c to the 
exhaust. To release the brake the handle 4 is moved to 
the left, which allows main reservoir air valve 8 to close 



r\ 



r\ 




Fid. FlG -«- 

Straight-Air Brake Valvb, 



102 DOUBLE CHECK VALVE 

and then open exhaust valve 9, so that air in the cylinders 
can pass out to the atmosphere. When handle 4 is in 
mid-position, both valves are closed so that they are. 
"on lap." 

A leather washer 6 prevents leakage from b to the 
atmosphere when the brake is applied; spring 7 holds 
shaft 2 against this washer when there is no compressed 
air in this part of the valve — see Fig. 3. 

To regulate the pressure of the air fed from the main 
reservoir to this valve, a G-6 Slide Valve Feed Valve is 
used, located on the pipe between the reservoir and brake 
valve and set to close at 45 pounds. This reducing valve 
regulates the brake cylinder pressure to the proper amount, 
and also restricts the flow of air and assists the engineer 
in making moderate applications. 

The Double Check Valve shown in Fig. 4 is located in 
the pipe between the triple valve and the cylinders, in a 
horizontal position so that it will not open or close by 
gravity. The triple valve is coupled to one end-, the 
straight air brake valve at the other. The brake cylinder 
can be coupled to either side, as shown, one side can be 
used for the safety valve, or a driver brake cylinder can 
be coupled to each side and the safety valve located in the 
pipe leading to the cylinder. Two of these valves are 
required, one on the engine and one on the tender, with 
a ?4-inch pipe connecting them to the straight air brake 
valve, the same as the 1-inch brake pipe connects the 
triple valve and automatic brake valve. 

Two safety valves are required, one for the engine and 
one for the tender, set at 53 pounds. 

When the straight air is used it moves valve 5, Fig. 4, 
over so gasket 7 makes a tight joint at b and the air 
passes through opening c to the cylinders, but cannot get 
to the exhaust port of triple valve. If automatic is applied, 
air from the triple valve moves valve 5 so the opposite 
gasket makes a joint at a and air passes through ports 
c 1 to the cylinders, but cannot pass to the straight air 
brake valve. Thus you see the double check valves auto- 
matically connect the brake cylinders to either the auto- 



DOUBLE CHECK VALVE 



103 



matic or straight air system and prevent air passing out 
of the exhaust port of one system while the other is 
being operated. 

When operating the straight air, move handle 4 over 
and you will feel the resistance of valve S ; a little practice 
will enable you to calculate the amount of air you allow to 
pass into the cylinders in a partial application; you can 




Fig. 3. 



104 OPERATING STRAIGHT AIR BRAKE 

follow up by admitting additional amounts of air, till if 
necessary, the brake is fully applied, of course, taking care 
not to shock the cars attached to the engine by too sud- 
den an application. If it is to be held fully applied leave 
the valve in application position, so as to feed up any 
leaks that may reduce the power. For a full, quick appli- 
cation the valve may be opened wide, as the reducing 
valve will stop the flow of air from the main reservoir 
when it reaches the pressure at which the reducing valve 
is set. A partial release can be obtained by opening and 
closing the valve 9 ; a quick, full release by moving 
handle 4 to exhaust position and holding valve 9 open. 

If the straight air brake is left on lap while the auto- 
matic is applied, when the automatic is released the double 
check valve may be shifted by the pressure of the air that 
may get in the pipe between the check and the straight 
air valve, if the check valve shifts and closes the opening 
at b the brake cylinder air cannot get out of exhaust port 
of triple, and thus cause the driver and tender brakes to 
stick. A new style of double check valve now in service 
prevents this trouble. When using automatic, handle 4 
should always be in full release position, holding valve 9 
open. The automatic brake valve when not in use should 
be on running position and at least 10 pounds excess 
carried to prevent triple valves "creeping on" at any time. 

Never apply both brakes at once while switching. 
When you use automatic be sure the other is in release 
position first. If necessary to use straight air on top of 
the automatic to hold the slack of train, when the auto- 
matic is to be released, remember that a movement of 
both valves to release is necessary to let off the locomotive 
brake. 

If wheels skid on a good rail, test the safety valves and 
the reducing valve; they should relieve any over pressure, 
whether from a reducing valve allowing too high a press- 
ure, or from a double application, that is, an application 
with the automatic while the straight air is still applied; 
this will give a higher pressure than if the automatic 



STRAIGHT AIR BRAKE PRESSURE 105 

has set full first and is almost sure to slide wheels ; there- 
fore must not be used. Straight air gives 45 pounds only 
in the cylinders at any time ; if the automatic is applied on 
top of this 45 pounds, the 70 pounds in the auxiliary will 
tend to raise the cylinder pressure close to 65 pounds. The 
safety valves should reduce it down to 53 pounds. 

Both safety valves and the feed valve should be tested 
at regular intervals with a gage to insure that they 
regulate the pressure properly. There should be Tees so 
located in the pipes that a gage can be readily attached 
for this purpose. 

39. Q. How should the automatic brake valve be 
carried when backing up the train, or when expecting the 
trainmen to set brake from rear end? 

A. On running position ; so the brake will be applied 
as soon as brake pipe pressure is reduced, when brake 
valve should be placed on lap at once. This also applies 
to pushing a snow plow if brake is handled from the plow. 
A few companies require that the brake valve be kept on 
running position all the time, when backing up a train. 
There is some difference of opinion as to the proper posi- 
tion of the H-5 valve, some carry it on holding position 
and use the independent valve to release the locomotive 
brake. The H-6 valve can be carried in running position. 

40. Q. How do you set and release the automatic 
brake? 

A. Reducing the brake pipe pressure operates the triple 
valve to apply the brake and restoring the original press- 
ure releases it ; this is the engineer's method. It can be 
applied from the train by opening the conductor's valve, or 
the angle cock at the rear of last air brake car. Pulling 
the hose apart at the couplings, a hose bursting or any 
bad leak or break in the brake pipe will set the brake. 
When the train breaks in two between air cars all air 
brakes on both parts of the train that are cut in set 
instantly. A brake can be set on a car that is alone by 
opening the angle cock to let air out of the brake pipe. 
In such a case the brake can be released by bleeding the 



106 GRADUATED APPLICATION 

auxiliary reservoir. If a brake is to be released from the 
train the auxiliary pressure is reduced by bleeding till it 
is lower than the brake pipe so the triple valve will open 
the exhaust port, or all the air is bled out of both reser- 
voir and brake cylinder. Usually the release spring in 
the brake cylinder will push the brake piston back over 
the leakage groove before the graduating spring moves 
the triple piston and slide valve to lap. 

41. Q. Can a gradual application of the brake be 
made, that is, with only part of its full force? 

A. Yes, by reducing the brake pipe pressure only a 
few pounds, say five to seven pounds for first reduction; 
this reduction is necessary to make brake piston move over 
leakage groove; a lighter reduction than five pounds will 
not always do this ; two to three pounds at each of the 
succeeding reductions, less than twenty pounds in all. 

42. Q. Why does this reduction of only a few pounds 
in the brake pipe pressure make a light application of the 
brake ? 

A. With a light reduction the triple piston moves 
down slowly, opening the air valve slowly; the air from 
the auxiliary reservoir passes into brake cylinder through 
graduating valve and a small port in the slide valve; as 
soon as the auxiliary pressure is a little lower than brake 
pipe pressure, the brake pipe pressure raises the piston, 
closing the graduating valve so no more air can pass into 
brake cylinder, thus setting the brake lightly. To illus- 
trate this, we will let out seven pounds of air, reducing 
brake pipe pressure from 70 to 63 pounds, that leaves 70 
pounds above triple piston, which moves the triple piston 
down towards the lower pressure, opening graduating 
valve 7 first; then moving slide valve 3 so that air can 
pass through it; when enough air has gone into the 
cylinder to reduce the auxiliary pressure below 63 pounds, 
the brake pipe pressure moves the piston towards the 
lower auxiliary pressure, closing graduating valve; 
another reduction produces the same effect, each time 
setting brake tighter till pressures equalize. The piston 



FULL SERVICE APPLICATION 107 

moves the main slide valve at the first reduction, but only- 
opens and closes the graduating valve at the following 
reductions till a full application is made. 

43. Q. How much do you reduce the brake pipe press- 
ure to make a full service application of the brake if the 
piston travels are the proper length? Why does a reduc- 
tion of twenty pounds set the brake "full on?" 

A. About 20 pounds, or from 70 pounds down to 50, 
or until the auxiliary pressure has equalized with brake 
cylinder. 

If the brake is in good order, with a piston travel 
of eight inches, a reservoir pressure of 70 pounds will 
fill the brake cylinder and equalize in both at 50 pounds, 
that will leave 50 pounds on top of triple piston. If the 
pressure on the brake pipe side or under the triple piston 
is any less than 50 pounds, the piston will stay down and 
hold the air valve open and pressures must equalize. 
One pound less will hold it down as well as any amount. 
When it has equalized, no more air will pass from aux- 
iliary to brake cylinder, pressure on brake piston will not 
rise above 50 pounds, and brake cannot be set tighter. 
Any reduction of brake pipe pressure that leaves it lower 
than auxiliary pressure will set the brake tight. If a re- 
duction of £0 pounds opens the air valve and holds it 
open, any further reduction will not produce any effect on 
it, and so far as that brake is concerned is only a waste of 
air, which must be supplied from main reservoir when 
you want to release brake. If any check valves in quick- 
action triples leak, a reduction in brake pipe pressure 
below brake cylinder pressure will let the brake leak off 
through this check into brake pipe. 

44. Q. What is necessary to have brakes set alike, 
with same reduction of brake pipe pressure and release at 
same time, with same increase of brake pipe pressure? 

A. 1st. The auxiliary pressures must all be the same 
to move triples down towards the same reduced brake 
pipe pressure. For example, if one auxiliary has 70 
pounds, another 60, a reduction of brake pipe pressure 



108 QUICK-ACTION TRIPLE 

below 70 will set the first brake, but it takes a reduction 
of below 60 to set the other one. 2d. All piston travels 
must be the same, for with a 20 pound reduction a short 
travel equalizes at a less reduction with a higher pressure 
than a long travel. When brake pipe pressure is increased, 
triple controlling brake with long travel will release first 
as the auxiliary pressure is lowest. Thus, brake with 
long travel equalizes last with lowest piston pressure and 
lets go first. 3d. That all triples and brake pistons are 
in good order and no leaks. 4th. That the main reser- 
voir pressure and volume are sufficient to move all triples 
to release quickly. 

45. Q. What is the difference between the plain engine 
triple valve and the car or quick-action triple? Why will 
not the plain triple do as well on a long train? 

A. A plain triple gets all its supply of air to set the 
brake from the auxiliary reservoir only; the quick-action 
triple gets it all from the auxiliary on a service applica- 
tion; when used with emergency it gets air from both 
train pipe and auxiliary. With a long train equipped with 
plain triples it takes some seconds to reduce the brake 
pipe pressure at last car and operate the last triple; the 
pressure in brake pipe is reduced slowly on last cars, 
which makes them set gradually; the brake pipe reduction 
is made at the engine only. The quick action triple has 
two separate actions; in one a service application operates 
only the plain part of it; in the other, plain and quick 
action parts are operated at once. A quick action triple is 
not always needed on an engine or tender, as they are so 
close to the brake valve that they operate quickly enough. 
In an emergency application the quick-action triple allows 
some of the brake pipe air to escape at the triple so that 
the brake pipe pressure is suddenly reduced at this triple; 
this also operates the next triple quick-action, which re- 
duces the brake pipe pressure still more, so that all the 
triples act quicker than when the reduction is made at 
the brake valve, and all the brakes are set at nearly the 
same instant. Thus there is less shock to the rear cars 



EMERGENCY APPLICATION 109 

of a full air brake train, as the action of the triples 
travels from one to the other faster than the slack can 
run up from car to car. 

46. Q. What is the emergency or quick application? 

A. If the brake pipe pressure is suddenly reduced at 
the first application 10 pounds or more, at the quick- 
action triple, so the graduating valve cannot reduce the 
auxiliary pressure at the same rate, auxiliary pressure 
will move piston by the service position, the emergency 
part of the triple valve is brought into action, opening a 
large port in the triple so the air goes from the brake 
pipe direct into the brake cylinder, not only setting the 
brake quick-action, but also reducing the brake pipe 
pressure suddenly at that point, instead of all the air 
having to go clear to brake valve to escape and reduce 
pressure. This sudden reduction sets the next triple in 
the same manner, which sets the next one, and so on to 
the last car; its action from one car to another is so quick 
that even on a long train it seems to catch all at once. 
When a quick-action triple takes air from the brake pipe 
and sets the next triple quick-action, • it also takes air 
from its auxiliary through a small port ¥j after the brake 
pipe has equalized, so the full application is made at 60 
pounds, about 10 pounds more than the piston pressure 
in full service application. 

If at the head end of train there are four cars with 
the triples, cut out at the cross-over cocks ; or four cars 
with brake pipe only, the reduction of brake pipe pressure 
at the fifth car will be so gradual that it will not work 
quick-action ; it takes a sudden reduction right at the 
triple to get the quick action. W^hen there are only two 
or three cars behind these cut-out triples, the small volume 
of their brake pipe will assist in having the quick-action 
jump over the cut out ones. At the rear end more than 
four cars can be cut out and get the quick-action as the 
''dead end" of the brake pipe will help to make a sudden 
reduction on the last cars. 

A sudden reduction of brake pipe pressure which will 



110 



EMERGENCY APPLICATION 



pull the triple piston down hard enough to compress the 
graduating spring and let piston make a full travel will 
open the large air port in plain triple valve, so brake will 
set somewhat quicker, but does not set with any higher 
piston pressure. 

47. Q. Explain the operation of the quick-action triple 
when used on the "emergency." 

A. A sudden reduction in the brake pipe pressure 
right at the triple must be made, so the triple piston will 
make a full stroke and open the emergency port in seat 




This cut shows the quick-action 

triple in emergency position. Port t 

registers with the notch in side of 

slide valve or the "removed corner" 

of slide valve, which is not shown in 

cut. Auxiliary air passes through 

this notch under port z into t on emergency 

piston 8. Poits z and t are beside each other, 

but no air passes from port z into /. 

QUICK -ACTION TRIPLE VAI<VE— EMERGENCY POSITION. 



EMERGENCY APPLICATION 111 

under slide valve, which will admit the auxiliary pressure 
over the emergency piston 8. This in turn pushes the 
emergency or rubber-seated valve 10 off its seat, and the 
brake pipe air can then go direct to brake cylinder through 
large port C, raising the brake pipe check valve 15 to do 
this. As soon as the brake pipe and brake cylinder press- 
ures have equalized, the check 15 seats itself, and a spring 
in this check valve pushes the rubber-seated valve 10 up 
against its seat as soon as the auxiliary and brake cylinder 
pressures are nearly equalized. At the same time that 
brake pipe air is passing into the cylinder, the air from 
the auxiliary is also going through a small port in the 
end of slide valve 3. This port is made very small to 
give the brake pipe air a chance to equalize into the brake 
cylinder first, then the auxiliary pressure equalizes with 
the brake cylinder afterwards, at about 60 pounds. The 
emergency valve 10 is used to hold the brake pipe air 
out of the brake cylinder, therefore in quick-action it 
must be moved off its seat against the brake pipe press- 
ure; this is done only when triple piston makes a full 
stroke suddenly. If it moves down slowly, the graduating 
valve will allow air to pass from auxiliary into brake 
cylinder before emergency port is opened, and reduce 
the auxiliary pressure as fast as the brake pipe pressure 
falls, so graduating spring will have power to prevent a 
full stroke of piston. 

48. Q. Can you get the emergency action of the quick- 
action triple while brakes are set with a service applica- 
tion? 

A. Not unless they are set with a light application. 
The pressure in auxiliary and brake pipe must be con- 
siderably higher than in the brake cylindejr, or the 
emergency piston will not move valve 10 off its seat, 
nor will check 15 raise to allow air to pass through. 
Then, if a partial service application has been made, the 
graduating valve can open first, which reduces the aux- 
iliary pressure some and retards the full stroke of the 
piston a little in opening the emergency port. Even if 



112 EMERGENCY APPLICATION 

all these emergency valves operate after a moderate 
service application, only a very little air will pass through 
them, not enough to affect the triples behind it, or raise 
the pressure in cylinder very much. See Q. 111. 

49. Q. Is it practicable to attempt to get the emer- 
gency action of the brake by suddenly recharging the 
hvakt pipe for one or two seconds and then opening the 
direct application port wide? 

A. No. The triple piston will not move till you have 
reduced the brake pipe pressure a little lower than the 
auxiliary pressure, and no air can pass into the brake 
cylinder from either brake pipe or the auxiliary till piston 
moves and opens the valves. By this movement you will 
partially release some of the brakes and may get a lighter 
service application the second time than you had at first. 
Don't try it. Unless you have time to recharge auxiliaries 
to 70 pounds, hang on to what you have. 

50. Q. Is it safe to try and retain air in a brake pipe 
in the emergency application, and why not? 

A. It is not safe as a general rule. In an emergency 
when life or property are in danger, you must act quickly, 
The point is to get stopped dead as soon as possible, and 
see about getting started afterwards. An emergency appli- 
cation is the last resort and you must get it when you 
need it. If you do not let nearly all the air out of a long 
b>rake pipe, some of the triples will not act quick enough. 
If three or four triples are cut out, or there are three or 
four plain triples close together at the head end of the 
train, the quick-action will not catch behind them and 
all the air must be let out at head end of train to reduce 
the pressure as quickly as possible. A full reduction of 
"20 pounds is necessary to set the plain triples on engine 
and tender so these brakes will do their full share. With 
a double header it is generally necessary to let the air 
out at brake valve of rear engine to catch the quick- 
action on the train. With a full train of quick-action 
triples a sudden reduction of 25 or 30 pounds at the 
•engine will catch them all and leave considerable air in 



QUICK- ACTION TRIPLE DEFECTS 113: 

the brake pipe, so you can release and back up out of 
the other train's way if the brake stops you in time. This 
is the only special exception to the general rule. It is 
easy to hold part of the air when making tests or in the 
instruction car; but when you think some one is going 
to get killed, it is not quite as easy as clear over to full 
emergency. 

51. Q. How does the quick-action triple operate on a 
short train, if graduating pin is broken? Or .the graduat- 
ing ports gummed up? 

A. With the emergency on a light service application. 
If the graduating pin is broken, the graduating valve will 
be held on its seat by auxiliary pressure, and the emer- 
gency port is the first one to open. 

If the graduating valve is gummed up or dirty so the 
air can not flow past it properly, the triple will work with 
emergency when you make a moderate service application. 
With a long train the emergency port is opened so gradu- 
ally that the air can get past the emergency piston and go 
to the cylinder without moving the emergency piston. 

52. Q. If while making a moderate service applica- 
tion your brakes would "fly on" and at the same time the 
air would stop running for a moment from brake pipe 
exhaust and then begin again, where would you look for 
the trouble? 

A. In one of the quick-action triples. This action of 
the brake valve shows that one of the triples is working 
quick-action only, in advance of the rest, even with a 
service application. - When the triple works quick-action, 
it takes some air from the brake pipe, reducing the press- 
ure so the equalizing piston seats for an instant. At the 
same time the black hand takes a sudden drop for an 
instant. Probably the graduating pin is broken, although 
a broken graduating pin in service is very rare. If the 
graduating spring 22 has been left out it is very apt to 
cause quick-action. If the triple piston or slide valve is 
gritty or badly gummed so it does not move freely, it will 
cause this trouble. 



114 QUICK-ACTION TRIPLE DEFECTS 

If the graduating valve or its ports are gummed up so 
that the air cannot flow past it out of auxiliary to equalize 
the pressures as fast as it flows out of brake pipe, this 
triple will be sure to work quick action. A quick-action 
triple that needs cleaning, or has the graduating ports 
defective in any way, is liable to work quick-action with 
a moderate service reduction. If the brake pipe exhaust 
elbow is gone from the brake valve it will allow so 
sudden reduction of brake pipe pressure that the triples 
will work quick-action on a very short train. 

Improper handling of the brake valve will also cause 
triple valves to go into quick action with a service re- 
duction. With a very long train it takes quite a few 
seconds to have the reduction made at the brake valve 
felt on the rear car. If you have overcharged the head 
end by full release position for fifteen or twenty seconds 
and then begin a service application, air is still feeding 
into the rear triples; this makes a reduction at the rear 
end and the brake valve one on the head end, the triples 
ahead of the middle of the train cannot keep up and 
•go into quick action. 

To locate one of these defective triples, close some of 
the angle cocks so as to use not over ten cars at a time, 
and make a moderate reduction, say five pounds, then 
make another of five more. If the brakes work quick- 
action you can be certain the defective triple is on one of 
these cars. After recharging, set the brake again with 
about seven pounds reduction, and note which brake has 
not set at all. Cut this one out and make another test, 
which will show if you have the right one. If you do 
not find it in the first set of ten cars tried, cut in some 
more and try them. The disabled triple will not always 
set at the first reduction, and will work quick-action at 
the second one ; it is more apt to give trouble in a short 
train than in a long one. 

53. Q. If with a quick-action triple, the brake should 
refuse to release, but kept blowing from the exhaust port 



QUICK-ACTION TRIPLE DEFECTS 115 

or pressure retainer, what would be the matter and what 
would you do? 

A. The emergency valve 10 was likely held off" its 
seat or was worn out and leaked badly. If out on the 
road and valve would not quit leaking after a few emer- 
gency applications, would cut out that brake. If the 
gasket between the triple valve and cylinder head on a 
passenger brake or next the reservoir on a freight brake 
had blown out, it would let auxiliary reservoir air into 
exhaust and the blow would soon be down to the capacity 
of the feed port in triple valve. A small leak past the 
emergency valve when the brake is set will soon equalize 
the brake cylinder and brake pipe pressures. With a 
sticky triple this brake might not release with increase of 
brake pipe pressure and wheels be skidded. Better cut 
out such a brake and bleed it. 

54. Q. Describe tthe construction and operation of the 
Quick Service Triple Valve, Type K. 

A. The quick service triple valve shown in the next 
illustration is similar to the ordinary quick-action triple 
in use for many years, but has some additional features. 
There is an additional air port y leading from the 
chamber Y between the brake, pipe check 12 and the 
emergency valve 10, up through the triple body to the 
slide valve bushing at c. This port c is covered by the 
slide valve so any air passing through port c must also 
pass through a port in the slide valve to get any farther. 
The graduating valve 7 is a small flat valve with a cavity 
v in its face, this valve rides on the back of the slide valve 
3 and moves each time piston 4 does. There is some lost 
motion between the shoulders of the piston stem and the 
ends of slide valve 3, so the piston can move this distance 
without moving valve 3, this allows the piston to move 
and close the feed port i as well as open and close the 
ports under the graduating valve without moving slide 
valve 3. On the reservoir end of the triple is attached a 
cage 29, containing a "retarded release" stem 31 and its 
spring 33. The later type of K triple is shown here, and 



116 



K TYPE TRIPLE VALVE 



below the triple is shown the first style of release stem 
and spring. A small pin 34 prevents stem 31 moving 
too far in the cage when taken off. There was no feed 
groove in the shoulder of piston 4 where it rests against 
the slide valve bushing when at its extreme travel in 
release position in the first K triples, so that in this posi- 
tion, air passing through feed port i could not get into 
the auxiliary. The later ones have a groove in this 
shoulder. When the piston and slide valve are in free 
release position the stem 31 and spring 33 are in normal 
position — not compressed — the exhaust port in slide valve 
3 is wide open and the feed ports open so brake pipe air 
can equalize to the auxiliary. In the triples used with 
10-inch brakes and larger ones, there is also a feed port 

7 35 3 6 A 5 



TO AUXILIARY 
RESERVOIR 




12 26 



OPERATION OF K TRIPLE 117 

through the slide valve that is open in free release. There 
is a small feed port through the slide valve that is open 
only in retarded release position which charges the aux- 
iliary very slowly. The feed port i around the piston 
is the same size in all quick-service triples, so most of 
the air in the large triples passes through the feed port 
through the slide valve. After the auxiliary has charged 
to standard pressure, which we will assume is 70 pounds, 
a moderate brake pipe reduction will move the piston 4 
to the right following the reduction. This movement first 
closes feed port i and moves the graduating valve 7 on 
the back of the slide valve 3 to close feed port and open 
the supply ports under it. The slide valve then moves, 
first closing the exhaust port and next opens the service 
ports in valve 3 to the ports in its seat. Auxiliary air 
then flows to the cylinder through port r. At the same 
time brake pipe air from chamber Y flows through port 
y, a port through slide valve 3, the cavity of the graduat- 
ing valve 7 and ports in slide valve 3 into port t in the 
seat, and thence around the emergency piston — which is 
not an air tight fit— into X and the cylinder. This small 
amount of brake pipe air passing to the cylinder is not 
sufficient to cause an emergency reduction, but causes the 
next triple to operate more certainly and thus applies 
all brakes in a train in less time than when the entire 
brake pipe reduction is made at the brake valve. The 
brake pipe air passing to the cylinder in a service applica- 
tion increases the pressure there so that a five-pound 
reduction in brake pipe and auxiliary will give about 
14 pounds in the cylinder as well as applying the quick- 
service triples in less time from front to rear of train. 
The air from the brake pipe also tends to give a higher 
pressure with long piston travel than with the old triples 
taking air from the auxiliary only. 

On account of the arrangement and size of the service 
ports the quick-service triples are not as liable to go into 
undesired quick action as the older form. When in quick- 
service position the ports are only open a portion of their 



118 OPERATION OF K TRIPLE 

full size to reduce the auxiliary pressure as fast as brake 
pipe pressure is ordinarily reduced at the brake valve. If 
the triple piston moves over enough to compress the 
graduating spring 22 a little, the service ports will open 
wide; this reduces auxiliary pressure so fast that the 
piston will not go to emergency position for a moderate 
reduction unless it is defective. When the brake valve is 
placed in full release and the brake pipe at the head of 
the train charged much higher than the auxiliary press- 
ures there, the quick-service triples there will move past 
free release position compressing the stem 31 and spring 
33 and the slide valve exhaust cavity will be moved far 
enough so the wide open port of this cavity will be 
beyond the exhaust port and the small part of the exhaust 
cavity will be in register with the port. This causes the 
air to exhaust from the brake cylinder very slowly and 
the quick-service triples at the head end that have the 
high brake pipe pressure hold their brakes set some 
seconds longer than when in free release position. As 
the brake pipe pressure reduces farther back in the train 
until it is not enough higher than the auxiliary to move 
the triple piston to retarded release position against the 
resistance of spring 33, the triples will all move to free 
release position as fast as the increase of brake pipe 
pressure reaches them. On a fifty-car train equipped with 
the quick-service triples, about one-third of them, or 
fifteen to twenty will go to retarded release and those 
next will release quickly. This tends to release the 
middle and rear cars of a long train before the cars next 
the engine are fully released, as the head brakes are 
retarded, the whole train will release at about the same 
time, and thus prevent the slack running out and break- 
ing trains in two or more parts when releasing brakes at 
a slow speed. To get the retarded exhaust of quick-service 
triples when the entire train is not equipped with them, 
these triples should be next the engine. When at the 
rear they do not retard the release any more than the 
ordinary quick-action triple. 



TYPE L TRIPLE VALVE 119 

55. Q. Describe the Westinghouse Type L Triple 
Valve. 

A. The Westinghouse L triple valve is designed for 
high duty passenger service, it is pipeless, that is, all air 
pipe connections are made at the pressure head to which 
the triple is bolted; it uses two reservoirs; one the 
ordinary size for that brake cylinder and a supplementary 
reservoir about twice the volume of the service auxiliary. 
In case this supplementary is not to be used when other 
cars in the train do not have it, a cock cuts it out from 
the triple valve, this cuts out the graduated release 
feature and the very high pressure with quick action. The 
L triple is a quick-service and a quick-action valve, the 
quick-service feature has been explained in connection 
with the K triple, and the quick-action also, we need not 
repeat all of it here, and it is understood that the student 
is familiar with the action of the ordinary quick-action 
triple. This triple does not have the retarded release 
through a small exhaust cavity that the K triple has, 
therefore does not use a retarded release spring, the ex- 
haust cavity is in the graduating valve, and is of the 
proper size to exhaust the brake cylinder air in the 
standard time. The exhaust valve is under control of 
the engineer, who by changes in the brake pipe pressure 
and the aid of the supplementary reservoir, can allow all 
the brake cylinder air to pass out freely, or hold it back 
and reduce the cylinder pressure a little at a time till 
down to nothing; by the control of the exhaust you can 
have a moderate cylinder pressure at the instant the stop 
is made. 

Two sectional views of the actual valve, a side eleva- 
tion and an end elevation and a diagrammatic view of 
the valve in full release and charging position are shown. 

In release position, or when running between stations 
both reservoirs charge at the same time and to the same 
pressure through the L triple. There is the usual feed 
groove i in the cylinder bushing to allow air from the 
brake pipe to pass around the triple piston; it is a small 



120 



TYPE L TRIPLE VALVE 



3» 26 25 27 20 29 30 




FULL RELEASE AND CHARGING POSITION. 

one, more to keep the brake pipe and auxiliaries equalized 
after charging than to do much of that work. There is 
a charging port / through the slide valve; open in release 
position only, that connects with cavity Y above the 
brake pipe check 15 ; air can pass by check 15 and go 
through the slide valve 3 to the reservoirs, but check 15 
prevents it getting back to the brake pipe during a reduc- 
tion. When a service application begins, this charging 
port in slide valve 3 is first closed as well as the port k 
leading to the supplementary through x, so no air can get 



OPERATION OF L TRIPLE 121 

out of there, air from the service auxiliary only is used 
in a service application, supplementary air remains bottled 
up till the triple goes to release position, when this large 
volume of air at standard pressure will quickly equalize 
with the service auxiliary at close to the standard press- 
ure, even before the brake cylinder air has escaped; this 
makes a quick recharge from the supplementary to the 
service auxiliary. If 90 pounds is carried, after a full 
service application the service auxiliary will have 70 
pounds, and the 90 pounds in the supplementary will 
equalize in both of them at over 83 pounds, air from the 
brake pipe will soon put the other 6 pounds in, 

Referring to the diagrammatic view, all the air ports, 
passages and cavities in the valve and seat are shown ; 
something that cannot be done in the view of the actual 
valve as many of the ports cannot be made to show in a 
correct sectional view. Air from the brake pipe enters 
at the lowest passage through a, e and g to h, forces the 
triple piston 4 to release and charging position, if not 
already there, and passes around the triple piston, through 
port i into R and the auxiliary reservoir. Air also passes 
through port k in slide valve 3 and x to the supplementary 
so it charges at the same time as the service auxiliary. 
Brake pipe air raises check 15 and goes through port r 
in the body of the valve and its seat, thence through port 
I in slide valve 3 to R, so air is passing into R from two 
sources. Port / is larger in the large triples than in the 
small ones, but feed-groove i is the same size in all of 
them. Any air that may be in the brake cylinder will 
pass through C, r, n, in valve 3, then through cavity w in 
graduating valve 7 into port m, and finally into P, the 
final exhaust. You will note that exhaust air must pass 
through a cavity in graduating valve 7, this will explain 
why a movement of the graduating valve will open and 
close the exhaust, t is the emergency port through which 
auxiliary air passes in over piston 8 when slide valve 3 
is back in emergency position. There are two pistons in 
this triple that operate only in an emergency application, 



122 OPERATION OF L TRIPLE 

piston 8 that does the same work as piston 8 in the 
ordinary quick-action triple and piston 25, called the by- 
pass piston, its duty is to open by-pass valve 27 to allow 
air in the supplementary to equalize with the service 
auxiliary in an emergency application. This piston is 
shown at the top in the actual triple. During a service 
application the auxiliary pressure remains equalized on 
both sides of piston 25 so it does not move. In an 
emergency application slide valve 3 moves back far 
enough so port c registers with d in the slide valve, this 
opens a communication between f on the inside of piston 
25, through c, d, m and r to the brake cylinder; auxiliary 
pressure in B forces it over and opens valve 27; 
this allows supplementary air to flow to the auxiliary 
and equalize at very nearly the standard auxiliary press- 
ure. If, at a service application, an emergency arises, a 
sudden reduction of brake pipe pressure at the brake 
valve will put the L triples into the emergency position, 
the by-pass valve will be opened and the supplementary 
air will pass into the brake cylinder and service auxiliary 
giving a high braking pressure, which the safety valve 
will hold till released the regular way. Port b connects 
with safety valve 33 in release and all service positions 
so the safety valve can blow down cylinder pressure to 
its adjustment at ordinarily 62 pounds. In an emergency 
application cavity q travels past port r so the brake 
cylinder is cut off from the safety valve and there is no 
escape of air at the safety valve in an emergency applica- 
tion, all the air is held in the cylinder till the brake is 
released the regular way. 

In a graduated service application there are two posi- 
tions of piston 4 and slide valve 3, the first one is quick- 
service position; in this, port o in valve 3 is brought in 
register with port 3/ in the seat, so air passing check 15 
can flow through y and 0, graduating valve 7 being moved 
back at that time air from will pass through the small 
cavity v in graduating valve 7, through the small port 
into cavity q and thence to C and the brake cylinder, this 



OPERATION OF L TRIPLE 123 

makes a gradual brake pipe reduction at the triple and 
starts the other triples in the rear of it, to service position 
quicker than the brake valve reduction would. Port z 
in slide valve 3 has been brought in register with r in 
the seat, graduating valve 7 having uncovered z at the 
top, auxiliary air also flows to the cylinder at the same 
time air from the brake pipe passes in. As soon as the 
auxiliary pressure is a little lower than that of the brake 
pipe and the reduction at the brake valve is stopped, the 
auxiliary reduction gets ahead of that in the brake pipe 
at h so piston 4 moves towards the right carrying with it 
valve 7 closing ports z and the small port into q, this 
stops the flow of air into the cylinder and holds it there. 
Another gradual reduction at the brake valve produces 
the same effect, till the pressures are equalized between 
the auxiliary and brake cylinders. 

If the train is a short one the piston and slide valve 
pass by the quick-service position to what is called full 
service position in which port o in valve 3 moves pasi 
port 3; in the seat so no air passes that way and port 3 
is opened full width to r, this takes auxiliary air to 
cylinder faster than in the quick-service position and 
tends to prevent the triple going into quick action on a 
short train. In quick-service position knob J on piston 
4 touches the graduating stop 21 without compressing 
it, in the full-service position it compresses the spring a 
little till its resistance will stop piston 4, this also aids in 
preventing quick-action applications with a service re- 
duction. It is the graduated or "step-down" release that 
requires the most study to understand. During a brake 
application the supplementary still holds the standard 
pressure we had at the beginning of the application. 
When the triple piston 4 and the slide valve 3 move to 
the right at the release, exhaust port n is in register with 
r in the seat, cavity w in valve 7 allows air from the 
cylinder to pass out through m to P. At the same time 
port k in the slide valve is in register with x in the seat, 
so supplementary air feeds into R and the service aux- 



124 GRADUATED RELEASE 

iliary. If the brake pipe pressure in h has been raised by 
the brake valve being left in full release so it is higher 
than the supplementary can equalize with R, piston 4 
will remain in rull release. But if the brake pipe pressure 
is raised a few pounds and the brake valve lapped, as soon 
as the supplementary air coming through port k can 
raise the pressure in R higher than the brake pipe press- 
ure in h, piston 4 will move back carrying graduating 
valve 7 with it, closing port k so the pressure in R will 
not rise any higher and closing port m so no more air 
can pass to the exhaust from the cylinder, this allows 
part of the cylinder air to escape, how much, depends on 
how long the exhaust cavity w connects ports n and m. 
Valve 3 is not moved, as the raise in pressure in R is 
only sufficient to move piston 4 and valve 7, when port 
k is closed and stops the rise in pressure. Another re- 
charge of the brake pipe and lapping the brake valve will 
move piston 4 and valve 7 so ports k and m will be 
opened and more air will exhaust from the cylinders, 
these recharges at the brake valve and exhausts at the 
triple will continue until all the air has escaped from 
the cylinder. After slide valve 3 has moved to release, it 
is a movement back and forth of the graduating valve 
that opens and closes exhaust port m, supplementary 
port k and brake pipe port j. The older makes of triples 
have the exhaust cavity in slide valve 3, the L triple has 
the exhaust cavity in graduating valve 7. This explana- 
tion and the illustrations will give a good idea of how 
to operate this triple, so we will not speak further of its 
operation. 

This type of triple valve is being modified and im- 
proved from time to time so we may expect it to do still 
more in the future than it does now. 

56. Q. How do you locate a leak that lets off the 
brake ? 

A. If it leaks off through piston packing leather the 
air will blow out of the hole in spring case or lower head 
in push down brake; with a pull up brake, around piston 



TRIPLE VALVE DEFECTS 125 

rod or through the vent hole in top head. A leaky brake 
pipe check valve 15 will let the air out of brake cylinder 
into the brake pipe, but only when brake pipe pressure is 
lower than cylinder pressure. This will be the case when 
hose bursts or train breaks in two, or engineer reduces 
the brake pipe pressure too much. In ordinary service 
stops, leaks at this point do not affect the work of the 
brake. 

A test for leaky brake pipe check valve 15 in the quick- 
action triples can be made at the brake valve. Reduce the 
pressure 20 or 25 pounds from 70, and if the air comes 
out full and strong and the equalizing piston seats its 
valve promptly without a leak, make another reduction 
of 15 or 20 pounds more. With this reduction the brake 
cylinder will have about 50 pounds and brake, pipe 30. 
If any brake pipe check valves leak, the 50 pounds will 
try to equalize with the 30, and make it more than the 
pressure above equalizing piston, which will raise and 
let air blow out of exhaust as fast as it comes past the 
check valve. 

To locate a leaky rotary or any leak in brake valve 
that lets off the brake, set the brake; close the cut-out 
cock at once; brake will stay set and black hand will 
raise or brake pipe exhaust open. Then open cut-out cock 
and brake will release through exhaust port of triple. 

To locate a leaky graduating valve, set the brake with 
a light application; it will release through exhaust port of 
triple about as quick as you can lap the brake valve. 
Then, after recharging the auxiliary, set with a full 
application and brake should stay set. 

When a leaky graduating valve lets off the brake with 
a light application, it is because the air from the auxiliary 
leaks past the seat of valve 7 into the brake cylinder 
until the auxiliary pressure is enough lower than brake 
pipe pressure so triple piston will move slide valve up 
into exhaust position, releasing air from brake cylinder 
through the exhaust port. This it cannot do with a full 
application, as in this case the air pressure has equalized 



126 BRAKE DEFECTS 

between the auxiliary and cylinder, so a leaky valve cuts 
no figure; air will not pass through after pressures are 
equal. A leaky piston ring in the triple makes this matter 
worse, as the brake pipe and cylinder pressures can 
equalize and stick the brake. A leaky triple usually is in 
bad order in other ways. 

57. Q. If the brake is defective and leaks off through 
piston packing, or any leaks in piping to brake cylinder, 
is it any advantage to let all the air out of brake pipe in 
such a case? 

A. It seems to make a leaking brake hold a little 
longer, but it is so short a time that it does not help very 
much to stop the train. A gage put on this brake cylinder 
will show that it only holds for a few seconds, and during 
that time with a light pressure. The proper way is to stop 
the leak. 

58. Q. What makes the driver brake so slow to take 
hold if coupled to a train when it works all right if engine 
and tender are working without a train? 

A. Generally it is because it leaks somewhere, so the 
air leaks out without setting the brake when a light reduc- 
tion is made for the train brake. See about the leaks the 
first thing. The piston packing leather gets dry and hard 
from being so close to the fire box and it needs soaking 
up with oil frequently in the summer time. Tallow and 
oil is good to put in driver brake cylinders, as it does 
not evaporate so quickly as oil and keeps the packing 
leather soft and pliable. To test for leaks, set the four- 
way cock in plain triple for straight air (if possible) ; 
or set the straight air; this will give you time to go 
around and find the leaks. If the piston leather leaks, 
the air will blow out of hole in the spring case or lower 
head of push-down brake. Using the brake valve on 
direct application position for service stops will sometimes 
kick the driver brake off, after setting the train brake. 
This is because when you use the direct application port 
to set the brake you make a heavier reduction at head 
end of the brake pipe than at rear end. The head end 



BRAKE DEFECTS 127 

triples equalize for this reduction ; air from rear end 
rushes up after you close the brake valve and releases 
head triples. This is another reason why the direct 
application should never be used unless you want the 
emergency action of every brake. 

59. Q. Why does the tender brake sometimes stick 
and refuse to let off till auxiliary is bled a little, when 
all the other brakes on the train release promptly? 

A. Generally because not enough excess pressure is 
carried. Always carry a sufficient excess if you want the 
automatic brake to work properly. Overcharging the 
head end of a long train will usually make the head brakes 
apply and if the brake pipe pressure drops a little they 
will stick till kicked off by going to full release for a 
few seconds. Some old tenders have 12 x 33-inch aux- 
iliary reservoirs for an 8-inch brake cylinder; if, in this 
case, the piston travel is short, the brake piston pressure 
is six or seven pounds higher than other brakes equalize 
at and brake pipe pressure must be raised correspond- 
ingly higher to release tender brake. Then the tender 
triple gets more sand and dirt in it than any other triple, 
which causes it to wear and get defective. A leaky triple 
piston packing ring will allow any brake to stick unless 
very high excess is used, as it will let air equalize past 
the triple piston into auxiliary without moving piston up 
to exhaust position. 

60. Q. If the brake pipe is charged up with a high 
pressure from main reservoir when brake is released for 
a second application stop, will the brake set again at once 
with a small reduction of brake pipe pressure? 

A. It will not set again until the brake pipe pressure 
is reduced below the auxiliary pressure. For example : 
If the brake has been set tight, the auxiliary pressure 
will be about 50 pounds for the first application; if you 
turn 90 pounds into brake pipe you must let 40 pounds 
out again, to draw brake pipe pressure below 50, before 
the triple piston will move; all this time your train is 
getting nearer the stopping point. This is one of the 



128 STICKING BRAKES 

reasons why you run by when trying to make a stop this 
way; it takes so long to draw your brake pipe pressure 
down where it was before. In case you expect to apply 
the brake at once after releasing it wholly or partly, put 
the brake valve on full release for an instant, just long 
enough to charge up the brake pipe its whole length, and 
then put it on lap. This movement will release triples 
and hold your brake pipe pressure so near the auxiliary 
pressure that the triple is ready to act instantly with light 
service application. This is the proper method of making 
partial release if you are going to stop too soon or expect 
that slippery track will skid the wheels just as the final 
stop is made. 

61. Q. Why are some of the train brakes more likely 
to stick on a long train after a light application than after 
a heavier one? 

A. Because after a light application the pressure has 
been reduced so little in the auxiliaries that the main 
reservoir does not have enough more pressure to move all 
the triples. A light reduction on a long train does not 
always move all the triple pistons and their feed ports 
remain open ready to take brake pipe air, which holds the 
brake pipe pressure down. With a heavy reduction the 
triples all operate, no feed ports will be open till triples 
release and the brake pipe pressure will raise higher at the 
moment of releasing brakes. This is a trouble peculiar 
to long trains only; small main reservoirs and sticky 
triples with leaky packing rings make it worse. 

62. Q. Is it possible to let off part of the brakes and 
leave part of them set? 

A. Yes. After a full application this can be done, 
especially if brake pipe pressure has been reduced much 
more than 20 pounds. When you go to full release, if 
the brake pipe is not at once charged up above the highest 
auxiliary pressures by the main reservoir air, as soon as 
the brake pipe pressure is a little higher than the lowest 
pressure in any auxiliary, its triple will move up into 
exhaust position, releasing that brake. Then this auxiliary 



BRAKES CREEPING ON 129 

will begin to recharge through feed port and help hold 
brake pipe pressure down till that auxiliary and the brake 
pipe are charged up high enough, when another brake 
will let off; and so on until all are let off. The brake 
with longest piston travel usually lets off first, because it 
has the lowest auxiliary pressure ; this operation takes 
place after a full application when piston travels are 
unequal. When pumping off the stuck brakes you have 
to raise the pressure in all the auxiliaries of the released 
brakes as well as in the brake pipe. When you think the 
brakes are releasing in this manner, lap the brake valve 
and pump up the excess ; when this is turned back into 
the brake pipe they will usually all let go. Do not attempt 
to work steam, you will risk a break-in-two. 

63. Q. Why do some of the brakes creep on when 
the train is running? 

A. Because there is a leak that takes air out of the 
brake pipe; this leak may be in the brake pipe, triple valve 
or auxiliary reservoirs. It can also be on account of the 
auxiliaries not having all equalized after releasing the 
brake. The auxiliaries at the head end of train will charge 
to a higher pressure on full release than the rear ones; 
when the brake valve is moved to running position the 
higher auxiliary pressure will cause the head triples to 
move to service position. If air is fed into the brake pipe 
faster than it leaks out, the brakes will not creep on. If 
air sanders use so much air that the pump can not supply 
air to hold up main reservoir and brake pipe pressures 
the brake will set; this is a main reservoir leak taking 
air out of brake pipe. 

64. Q. How can these brakes be released the quickest 
and surest way? 

A. If a main reservoir leak reduces brake pipe press- 
ure, shut off the escape of air if possible and run the 
pump faster till brake pipe pressure is raised so brakes 
will release. If a leak from brake pipe sets the brake, see 
that you have excess pressure first, then turn it back into 
brake pipe by moving the brake valve handle from run- 



130 STICKING BRAKES 

ning position to full release just long enough so the rush 
of air from main reservoir will charge up the brake pipe, 
and putting it back to running position before any of the 
auxiliaries are charged any higher. This forces the triple 
valves of the sticking brakes up into release position, so 
air from brake cylinder exhausts and does not give time 
to raise the pressure in any reservoir. Sometimes this 
must be done a second and third time to release all of 
them. If brake valve is held on full release long enough 
to charge a reservoir higher than the standard brake pipe 
pressure, that brake will be sure to set as soon as brake 
valve is returned to running position. This is the case 
when the feed ports are too large in proportion to the 
auxiliaries that they supply. 

65. Q. If governor is set at 70 pounds with D-8 
valve or any brake valve of that type, and brake pipe is 
charged from main reservoir higher than that pressure, 
is the brake apt to creep on? 

A. Yes; the pump is stopped and will not start again 
till brake pipe pressure is lowered to 70 pounds. The 
excess valve will remain shut so no air can pass into the 
brake pipe, and if there are any leaks the train pipe press- 
ure will drop. During this time brake is pretty sure to 
go on. 

66. Q. How can this be avoided? 

A. By not allowing main reservoir to charge brake 
pipe and auxiliaries at over 70 pounds. When standing 
at a water tank, or any stop, with brakes set, the main 
reservoir pressure is apt to run very high. If all of this 
is turned into brake pipe and allowed to equalize at over 
70 pounds, with brake valve carried in full release reg- 
ularly, there is no way to prevent the brake setting if 
brake pipe leaks. In this case, set it a little and at once 
release it; this will reduce the brake pipe and auxiliaries 
below 70 pounds, so pump will go to work and you can 
hold brake off. 

67. Q. In making a stop how should you release the 
brakes on a freight train? On a passenger train? 



RELEASING BRAKES 131 

A. On a freight train, not till it has entirely stopped, 
or you run the risk of train breaking in two. The brake 
pipe pressure on a long train is increased next the engine 
first; hence brakes let go there first; even if it is only a 
few seconds sooner. Part of the shock is from unequal 
piston travel, which gives unequal piston pressure ; brakes 
with long piston travel let go first after a full application. 
With a "part air" train the slack of entire train runs up 
against the head cars ; releasing brake while train is 
moving slowly, is liable to part the train; working steam 
before slack is all evened up in train is sure to break it in 
two. The ET brake and K triples will hold the slack 
against the engine. Using pressure retainers on the head 
end of such a train or the Straight Air brake on engine 
will hold the slack all bunched till all triples have released 
when retainer handle can be turned down or engine brake 
released. 

With a passenger train, release should be made just a 
few feet before the train stops, so there will be just 
enough power to stop the train and avoid tilting the 
coach truck forward at the instant the train stops. If 
the brake beams are hung from the body of the car the 
truck will not tilt forward, but there will be a shock at 
stopping if the brake power is severe. 

68. Q. Why should a brake on a short passenger train 
be let off just before coming to a full stop? 

A. Because, as most all coaches have outside hung 
brakes, the brake shoes pull down on the forward end of 
the truck and push up on the back part of the truck and 
thus tilt the truck; if brake is not let off until after the 
train stops, when the truck rights itself it rolls the wheels 
back a little and throws the body of the coach back, 
annoying the passengers, even if it is not severe enough 
to throw them against the seats. This trouble is not felt 
so plainly by the engineer when he has a good driver and 
tender brake, as the brake on the coach is what jerks the 
coach. Then less power is required to stop a train going 
very slow, as at the instant of stopping, than when run- 



132 TWO-APPLICATION STOP 

ning at full speed; if power enough- is left on to hold a 
train at full speed, it must stop very forcibly at slow 
speed. The brakes should begin to release about half a 
rail length from where the train finally stops ; a little 
farther if going very fast, a little less if a very slow 
stop is being made. Practice will teach you the distance. 
There is an exception to this rule in the case of a very 
long passenger train, say over twelve coaches, especially 
if it is not vestibuled and the buffer spring slack all taken 
up solid .between the cars. Experience will teach you that 
in stopping a train of this length less shock will be given 
the front end of train if brake is held on moderately tight 
just at the instant of stopping till train stops; i. e., handle 
a very long passenger train about the same as a freight 
train of the same length. 

69. Q. How should a "two application stop" with a 
passenger train be made? 

A. Make a full application when running at a high 
speed so as to have a high brake power at high speed. 
When the speed is reduced to 15 or 18 miles an hour, and 
you are stopping short of the desired point, go to full re- 
lease for an instant, just long enough to start all triples 
to exhaust, with the ET brake, stop on running position 
for an instant to partially release the engine brake, then 
begin the second application at once by a moderate reduc- 
tion which should set all brakes at a moderate power. 
You can increase the brake power with another reduction 
so as to stop at the exact point, and, if necessary, leave 
the brake set without having power enough to tilt the 
trucks and shock the passengers. This method reduces 
the risk of sliding wheels, as brake is set tight at high 
speed when wheels do not slide, then let off and set with 
less power at slow speed. With the L type triples the 
brake can be released a little at a time just before the 
stop. 

70. Q. Describe the position of the handles to all 
valves and cocks in the air brake and signal equipment, 
whether open or shut. 



THE BRAKE PIPE 133 

A. All the handles, except to angle cocks, stand at 
right angles or crosswise of the pipes when they are 
open; parallel to pipe when cut out, plain triples and 
pressure retainers follow the same rule, their handles are 
horizontal or crosswise when cut in. The crooked handle 
of angle cock is parallel with pipe when cut in. This is 
so the hose will protect handle from being struck by any- 
thing flying under the car and getting shut off, as the 
old style straight handled cock is liable to. A small 
groove square across the end of plug shows whether cock 
is open or shut, as the groove runs same way with hole 
in plug. 

71. Q. Do you understand that all air cars in a train 
should be connected and brake pipes charged with air, 
whether brakes are cut in or not? Why? 

A. Yes. All brake pipes should be coupled up and 
air working through them, so that if the train breaks in 
two anywhere in the line, all brakes will be set that are 
working. Interstate Commerce Commission rules say so. 

72. Q. What should be done with a car on which the 
brake pipe is broken? 

A. If it cannot be plugged at leak and allow air to 
pass freely to cars behind it, it must be switched behind 
all other air cars; have air in hose that is coupled to next 
car in front; brakeman should look after that car and all 
behind it. If you have two J^-inch air brake hose, the 
signal hose can be taken off signal line, brake hose put on, 
and signal line used for brake line through that car 
to get air back to other cars. 

73. Q. If the pipe at one end of the car should come 
loose, would you consider it dangerous? Why? 

A. Yes. If the pipe at end of car gets loose so cock 
will bounce up and down and strike the handle end of 
plug against the dead wood or any part of car, it is liable 
to work shut gradually. This is caused by the spring 
which holds the plug in its seat, turning the plug a little 
each time it strikes. If the spring is wound one way, it 
works open; if the other way, it works shut. The later 



134 INSPECTING BRAKES 

style of angle cock handle prevents the plug turning 
around. 

74. Q. 1. After coupling to train why should you 
not immediately try to apply the brakes for inspection? 
2. How long should you wait? 

A. Because you must wait till a full pressure of 70 
pounds is stored in auxiliaries so a full application of 
brakes can be obtained to get the piston travel. The time 
you should wait depends on the pressure maintained in 
the brake pipe from the moment of coupling on; if 70 
pounds is held steadily, two and one-half minutes is the 
shortest time for some of the older makes of triples. The 
triple valves of late design charge to 70 pounds in about 
seventy seconds. The pressures must be equaF in all 
the auxiliaries, even if it takes longer before testing. 
When the governor stops the pump with the standard 
pressures shown on both hands of the gage it is usually 
long enough. 

75. Q. Should the train brakes be inspected? How? 
When? Why? 

A. Yes, by applying them with full service application 
in the same manner as for a station stop with a moving 
train; then examine each car to see that the piston travel 
is the proper length and that there are no leaks that will 
let brakes off; then release them and examine each car to 
see that all release and that there are no leaks through 
exhaust port. They should be inspected at all terminals 
and tested whenever train breaks in two, or cars are taken 
on or set off, as the wrong angle cocks may be closed or 
left closed at such points. This is necessary because it is 
not safe to depend on a brake till it is shown that it will 
set and release properly. Hand brake should always be 
let off before testing. If pressure retaining valves are 
tested they should be turned up after the first test is com- 
pleted, a reduction of ten pounds made in brake pipe, and 
the brake pipe recharged to release the triples. The re- 
tainers should then be examined to see that they are all 
quiet; handles should then be turned down. If they are 



INSPECTING BRAKES 135 

in good order the air held in brake cylinder will come out 
as soon as handle is turned down. If no air blows out the 
retainer is useless, look for leaks at pipe joints and brake 
cylinder packing. 

76. Q. Would you consider a train safe to leave with 
if the brakes had been tested by opening angle cock at 
rear of train? How would this affect your main reservoir 
pressure? 

A. No, sir! not unless some other test has been made. 
This would not set all the brakes unless the brake valve 
was on lap. It would draw down main reservoir pressure 
and waste air without doing any good. This test is only 
good to show that air hose are coupled, angle cocks open 
and brake pipe charged from engine to last car. 

77. Q. If with 70 pounds brake pipe and auxiliary 
pressure you release the brake and apply it again imme- 
diately, would you expect to obtain the same power you 
had before? How long would it take to regain the 
original pressure? 

A. No, sir! never. About forty seconds, if main 
reservoir had 35 or 40 pounds excess over auxiliaries, 
sometimes less time. The feed ports in triple valves 
which regulate the time of charging are not always the 
proper size for the reservoirs they supply. A short train 
and light application would reduce this time to twenty 
or twenty-five seconds. Generally it takes longer than 
the tests show it with everything in good working order, 
for the feed ports are not always clean and strainers free. 
The pressure at which auxiliary equalized after first ap- 
plication is what you begin with on second application 
after first release, generally it is fifty after first full 
application ; with full release of brake and immediate 
application you get thirty-five and a little more on second 
full application ; the third time you will have less than 
30 pounds piston pressure. 

With the High Speed brake pressure of 110 pounds 
you can make two successive applications with 20 pound 
reductions and a release between before you get down 



136 SIZE OF FEED PORT 

to 70 pounds with the type L triple, the supplementary 
reservoir recharges the service auxiliary almost instantly. 

78. Q. Can an auxiliary reservoir be recharged with- 
out releasing the brake? 

A. No, not if the triple valve is in good order. The 
ports are so located in the triple valve that the feed port 
through which auxiliary is charged does not open till after 
exhaust port is open, which releases the brake first, 
recharge the auxiliary afterward. By the use of a press- 
ure retaining valve, which holds some of the air in the 
brake cylinder, the auxiliary can be recharged without 
releasing the brake entirely. If an auxiliary is recharged 
before the triple is moved to exhaust position, brake pipe 
pressure will not be able to move the triple, and the 
brake must be bled off. 

79. Q. Why does it take so long to regain the original 
pressure in the auxiliaries after releasing brakes? 

A because the feed port in the triple through which 
the air passes from brake pipe to auxiliary is small. This 
feed port is shown at m in the plain triple, and at i in 
the quick-action triple. It is necessary to have this port 
small for two reasons ; first — when setting the brake, the 
feed port must be small or when brake pipe pressure is 
reduced at brake valve for a light service application, the 
auxiliary air could flow around the triple piston through 
the feed port i as fast as it is taken out of brake pipe; 
so triple piston would not move. If the feed ports .were 
larger, when brakes are to be released, it would be im- 
possible to charge up a long brake pipe from the engine 
and hold the pressure up quick enough to release all the 
brakes at as nearly the same instant as possible, as the 
first few ports to open would take some of the brake pipe 
air and hold the pressure down ; if they were large 
enough a few of them would do this. The quick-service 
triples and L triples are now arranged to help this matter 
out. See questions 46 and 55. These feed ports must 
be the proper size for the auxiliaries they supply, so 
different sized auxiliaries will charge to the same pressure 



LEAKAGE GROOVE 137 

in the same time from the same brake pipe. The auxiliary 
reservoir for a 10-inch coach brake holds about 3,100 
cubic inches, that for an 8-inch freight brake holds about 
1,620 inches ; therefore a feed port for a 10-inch brake 
reservoir must be the right size to pass nearly twice as 
much air through in the same given time as for an 8-inch 
brake. This is the reason for using only the proper triple 
for each reservoir. Then the reservoirs are a certain size 
for the brake cylinders they supply, so an auxiliary press- 
ure of 70 pounds will equalize with brake cylinder of 8 
inches piston travel at 50 pounds. This in turn gives a 
standard piston pressure for which to arrange the brake 
leverage on each car or engine, so as to get the full 
effective braking power. The older style of plain triples, 
F-24, used with 8-inch engine brakes, have feed ports 
the proper size for 12 x 33 auxiliaries. This gives a 
quicker recharging and a prompter application with these 
brakes in switching service. If engine brake creeps on 
from this cause when coupled to a train they are easily 
released from the brake valve as they are close to the 
brake valve and main reservoir. The present style of 
plain triples, G-24, have the proper sized feed ports for 
the 8-inch brake. 

80. Q. Where are leakage grooves located? What 
are they for? Is it necessary to allow for them when 
applying the brake? How do you do this? 

A. Leakage grooves are small grooves cut in the 
inside of brake cylinders at the top or side. The later 
freight brake cylinders have them at the side.. When the 
brake piston is in release position this groove is uncovered 
so that a small amount of air passing into the brake 
cylinder from a very light application, or when the brakes 
are creeping on, will escape through the groove without 
moving the piston. When the triple valve is in relea.-e 
position any air that gets into the cylinder from leaks can 
pass out through the exhaust. They also prevent the 
brake holding when the piston travel is taken up too 
short. In old equipment they are long enough so that a 



138 PISTON TRAVEL 

piston movement of three inches is necessary to cover the 
groove, in later equipment they are much shorter. It is 
necessary to allow for them at the first reduction by mak- 
ing it strong enough so that the brake piston will go far 
enough at the first movement to cover the groove. Five 
to seven pounds reduction should do this ; a short train 
does not take as heavy a reduction as a long one. The 
leakage groove must be covered at the first reduction or 
the air passing into the cylinder will be wasted, a number 
of small reductions will waste all the air so train cannot 
be stopped. This is a common fault in operating the 
brake. If the hand brake is set on a coach or the piston 
travel shortened so the leakage groove is not covered, 
that brake will not hold. 

81. Q. Does the difference in travel of pistons in 
brake cylinders increase or decrease your braking power? 
Why? 

A. Long piston travel decreases the braking power 
because it gives less air pressure on piston, short piston 
travel gives higher piston pressure. With light applica- 
tions this difference is more marked than with a full 
application. A 10 pound reduction will apply a 4-inch 
travel brake solid, while it will not give any braking 
power with an 11-inch travel. With 8-inch piston travel, 
70 pounds auxiliary pressure gives 50 pounds on piston 
per square inch. An inch difference in the travel make 
close to two pounds in pressure, thus 7 inches would give 
nearly 52 pounds, 9 inches a little over 48 pounds. The 
piston travel can be correct with a heavy car and high 
leverage, and the shoes will not clear the wheel much 
when released. If levers and brake beams spring much 
with 8-inch travel, the shoes will not have much slack 
when let off. Brake levers may catch on something so 
piston travel is correct and shoes not touch the wheels. 
With the straight air brake or the distributing valve the 
piston travel does not affect the pressure on the brake 
piston, as these valves do not take air from an auxiliary 
as the triple valve does. 



CUTTING OUT BRAKES 130 

82. Q. How do you cut out the brake on engine and 
tender without interfering with the train brake? 

A. By turning the four-way cock in top of old style 
plain triple so the handle is at an angle of forty-five 
degrees ; this will lap all ports and allow no air to pass 
from brake pipe or auxiliary to brake cylinder ; see that 
brake is entirely released first, and open bleeder in aux- 
iliary. With the later type of engine triple the cut-out 
cock is in the cross-over pipe, so closing the cock cuts 
out the triple. Open bleeder in auxiliary so the brake 
cannot creep on from a leak in the triple. To cut out the 
locomotive brake from the distributing valve, shut the 
cock in the pipe leading to the cylinders. To cut out 
the automatic action of the distributing valve close the 
cock in the brake pipe connection. 

83. Q. What is the difference between cutting the air 
out from a car and cutting it out from a brake? 

A. Shutting the angle cock at the end next engine 
cuts out that car and all behind it; shutting the cross- 
over cock between brake pipe and triple cuts out that 
brake only and allows all the rest to operate. 

84. Q. If one brake beam under a car was broken 
"how would it affect that brake? How would you cut out 
the brake on that car and allow air to pass to other cars? 

A. If one brake beam or rod is broken, the brake on 
that car is useless and it must be cut out by shutting the 
cock in the cross-over from brake pipe to triple, or by 
turning the four-way cock in plain triple. This will allow 
air to pass through brake pipe to other cars without 
operating disabled brake. Be sure the brake with plain 
triple on either engine, tender or coach is released before 
four-way cock is turned, as no air can get out of brake 
cylinder after cock is turned. All quick-action brakes can 
be bled by opening the bleeder in auxiliary reservoir and 
allowing all air to escape, as the cut-out cock does not 
close the communication between brake cylinder and the 
bleed cock in auxiliary. 

85. Q. In going down a long, steep grade how would 



140 HANDLING TRAINS ON GRADES 

you handle the brake to control the train? Why is it 
necessary to recharge the auxiliaries on a hill? How is 
this done? 

A. Air braked trains on a long, steep grade must be 
taken down at a moderate speed in order to control the 
train; much less brake power will hold it at a slow speed 
than a fast one. If the train once gets the start of you it 
may not be held at all. Run slow enough so you will not 
need all the brake power to steady the train or you will 
not be able to stop when necessary. When first passing 
the top of a long, steep down grade, set the brake and 
see if you can stop; if satisfied, release and go on, if not 
satisfied the brakes will hold train, call for help and get 
stopped. 

Leaks in brake pipe, auxiliary, or brake cylinder press- 
ures make it necessary to recharge; very few if any trains 
are absolutely air tight. If brake pipe leaks, the brake 
will set at full power, which should stop the train; this 
will call for a release and recharging to standard pressure. 
Auxiliary or brake cylinder leaks will reduce the braking 
power so train will run away; to avoid this disaster it is 
necessary to recharge the auxiliaries frequently; you can 
then hold the auxiliary pressure up close to the standard 
amount all the way down the hill and have plenty of 
brake power. As triple valves release a brake and re- 
charge the auxiliary afterward, to hold the brake set while 
auxiliaries are recharging, pressure retaining valves are 
used, which hold some of the air in the cylinder after 
triple has gone to release position. Before starting down 
the grade turn up the handles or retainers, use as many 
as possible and not have them stop the train at any of the 
let-ups in the grade. The more retainers used the less 
hot wheels, as the holding power is on a greater number 
of cars ; if the full brake power is used on any cars all the 
way down a long hill the wheels are liable to get so hot 
as to damage them. Make a moderate application at first; 
when the train slows down, release and leave brake valve 
in full release position to recharge as quickly as possible, 



HANDLING A TRAIN 141 

which should not take over forty-five seconds. On the 
next application, a light reduction will usually steady the 
train, as with retainers used the pistons are over the 
leakage grooves and considerable pressure held in the 
cylinders. Light reductions give more power to brakes 
with retainers working than heavy reductions without 
the retainers ; this saves both brake pipe and auxiliary 
air. Pick out places where sharp curves or let-ups in 
the grade slow up the train to recharge auxiliaries. Air 
braking on a long hill should be learned on that particular 
hill — no exact rule can be set down; the instructions here 
given are general. To test the brake power developed on 
various cars, feel of the wheels at the bottom of the hill 
when possible; cold wheels on some cars and hot wheels 
on others show unequal braking power. Use the in- 
dependent engine brake while recharging, this will help 
hold the train. 

86. Q. What is the difference between handling a long 
train having part air in front and one entirely of air? 

A. A great difference. It requires more skill and 
practice to make a good stop with a part air train than 
with a full air train. With part air you must be careful to 
bunch the train so slack will run up easily against the 
air brake cars before setting the brake very tight ; this 
takes some seconds. If you make a second reduction 
before the rear end feels the effects of the first one, the 
two light applications make one heavy one, as far as the 
shock to the rear cars is concerned. When backing up, 
extra care must be taken, or train will break in two and 
merchandise be damaged in cars. With a full air train 
the first reduction of brake pipe pressure takes so much 
longer to start all the triples to work that you must wail 
about as much longer after the brake pipe exhaust stops 
flowing before making a second reduction. With a long 
all air train and new empty cars with short piston travel, 
or coaches on the rear end, it is a good rule to apply the 
brakes before shutting off steam, while the train is 
stretched, this prevents the higher power brakes at the 



142 DOUBLE HEADING 

rear pulling the train in two. The brakes are longer in 
releasing, and this requires more time after releasing 
before the train runs free. 

87. Q. If you had a freight train with "part air" cars 
in operation and you used the emergency application, 
would it make any difference whether the slack was out 
or not? In case there was a shock, on what part of the 
train would it fall? 

A. Using the emergency brake with part air train 
always sets the head end hard and solid; if slack is all 
run up against the engine the shock is not as great. In 
any case the rear end gets all the damage ; the weakest 
cars and draft gear behind air cars suffer. Empty flat 
cars next the air are likely to be wrecked. 

88. Q. Which engineer should handle the brakes in 
double-heading, and what should the other engineer do? 

A. The leading engineer should handle all the brakes 
when double-heading, as he is the only man who can see 
clearly all the signals and the condition of the track ahead, 
so as to act promptly to stop the train when necessary. 
The following engineer should shut the cut-out cock 
under his brake valve, which should be in running posi- 
tion with the 1892 valve, on lap with the H-5 valve, on 
running with H-6, keep the pump running and a full 
supply of air. If there is no cut-out cock, place brake 
valve on lap so no air can get into the brake pipe from 
his main reservoir and plug up train pipe exhaust elbow, 
so that when head engineer releases brakes the brake 
pipe air will not escape through second brake valve. If 
cut-out cock works open or is left open so main reservoir 
air feeds into brake pipe; when the leading engineer 
makes a service reduction the air from the following 
engine will hold the equalizing piston of head engine up 
so that brake pipe exhaust will blow strong and con- 
tinuously. If head man is sure that second engine is 
feeding into the brake pipe when brakes are to be set, 
he should go to emergency at once, whistle for brakes, 
get stopped or have second cut-out cock closed. The 



BURSTED AIR HOSE 143 

emergency port of first brake valve will take air out of 
brake pipe faster than the second pump and reservoir can 
supply it, especially if second valve is on running position. 

When testing the train brakes from a double-header, 
be sure that main reservoir air of following engines is 
cut out from brake pipe and that the test is properly made 
from leading engine. 

If the rules allow it and a definite arrangement is made 
between the engineers, the second man can assist in releas- 
ing stuck brakes or in charging auxiliaries by opening his 
cut-out cock when signaled to do so with brake valve in 
full release. As soon as train is moving cut-out cock 
should be shut so the leading engineer can stop the train 
at once if necessary. 

The rule to carry brake valve on running position with 
cut-out cock shut varies on different railroads. One 
prominent system requires that the brake valve be carried 
on emergency position so that in case of necessity brake 
will go on at once if cut-out cock is opened. Rules of 
your own road apply in this case to position of valve. 

89. Q. What would you do if an air hose burst? 
How would you know it? Should you have extra hose? 
Of what kinds? 

A. Put brake valve on lap; whistle out a flag. If in 
a dangerous place to wait, or when a train is close behind, 
shut the first cock ahead of bursted hose ; let off brake 
on head end from engine; bleed the cars behind bursted 
hose; get to a safe place and replace the bursted hose 
with a new one. If with bad grades or all air train, put 
in a new hose anyway, if possible. It would be known 
at once, because brake would set; black hand would 
drop way down ; main reservoir pressure would also run 
down quickly. Put brake valve on lap to save your main 
reservoir air. To locate the bursted hose put brake valve 
on running position just so you will keep a little pressure 
in the hose and trainmen can hear the air blowing out of 
bursted hose and find it. 

Extra hose chould be carried on engine, one of each 



144 BREAK-IN-TWO 

kind used. Trainmen should have a standard brake hose, 
a signal hose and one double-end or splice coupling to use 
in case drawheads or coupling of cars are so long the 
regular hose and couplings will not meet each other. 

90 Q.. What course would you take should your train 
break in two and set the brakes? 

A. Put brake valve on lap, shut off steam, whistle out 
a flag, shut the open angle cock on rear end of last car 
connected to engine, let off brakes on head section from 
the engine. When they are released and you get a signal 
to do so, back up to rear section ; after coupling up to it, 
if brakes cannot be let off from engine, bleed a few of the 
sticking ones at back end of train until train can be 
started. Be very careful to shut the bleeder as soon as 
air begins to escape from triple exhaust port or you will 
set some of the others, and that will hold the train longer 
than necessary. All air bled out is wasted; it is done only 
to save time, which is valuable in a case of breaking in 
two. If you break in two or burst a hose on a bad grade, 
shut both angle cocks next the opening in hose, this will 
save any air that leaks past the triples into the brake 
pipe and hold leaky brakes set till you are ready to release 
them to move the train. 

91. Q. Do you know what the pressure retaining 
valve does? And how? If the pipe leading to this valve 
should break off would you plug it? If you did, how 
would it affect the brake? 

A. The pressure retaining valve holds some of the 
compressed air in the brake cylinder after the triple valve 
has moved to exhaust position. It is attached to exhaust 
port of triple valve by a piece of pipe and placed where it 
can be conveniently reached when train is in motion. 
When set to operate, its handle is turned up to a horizon- 
tal position, which closes the direct opening, so the air 
goes out slowly under a weighted valve ; and then passes 
out of the case of valve through a small opening so air 
escapes slowly. When pressure falls- to 15 pounds per 
square inch in brake cylinder, this valve shuts off the 



PRESSURE RETAINER 145 

escape altogether and holds the air in there, keeping the 
brake set at 15 pounds ; this allows the auxiliary reservoir 
to be recharged to full pressure again. It is used on long, 
steep grades. If the pipe leading from the triple valve 
exhaust to the retainer was broken off that retainer would 
be useless. The pipe should never be plugged, as that 
brake would not let off at all ; there would be no way for 
the air to get out of the brake cylinder. 

The old style t retainers held 15 pounds ; there are 
other styles now made with heavier weights to hold 
more. A later style has two weights, by placing the 
handle in one position both weights come on the valve, 
in another position only one weight bears on the valve, 
this varies the pressure at the will of the trainman, who 
turns up the handle with 50 pounds as the maximum. 

92. Q. When air blows out steadily from the pressure 
retaining valve, should it be closed or left open? 

A. Left open by all means. The air that blows out 
there comes from a leak in the triple valve ; shutting the 
pressure retainer only stops air coming out there and 
sets the brake, or if leak is a small one, makes it go out 
through the leakage groove in the brake cylinder. If 
pressure retainer is turned up, even if the brake does not 
set right off, it will stay set when engineer sets it and 
tries to let it off. Never turn up retainers unless you 
want to hold the brake set the next time engineer releases 
it. If the pressure retainer is broken off or the pipe lead- 
ing to it from triple is broken or leaking badly, it does 
not affect the operation of the brake in any way, except 
that the retainer cannot be used on that car. If retainer 
is broken off and pipe plugged the brake cannot be re- 
leased at all from the engine, as there is no way for air 
to escape from triple valve exhaust. If there is a leak 
in pipe from triple valve to retainer, the retainer is of no 
use, as air will escape from the pipe at leak when retainer 
is set to work. Sometimes the pipe to pressure retainer 
gets stopped up so air cannot get through it, in which 
case the brake will set once and not release till bled off. 



146 AIR SIGNAL 

It is not unusual to find nests of insects in the pipe right 
at retainer. Pressure retainers are put on all freight 
cars used in interchange service. Very few coaches have 
them, only those running on mountain roads. Sleepers 
and official cars usually have retainers. They are used 
on level roads extensively to hold the slack bunched in a 
long train; in this case they are usually applied to the 
driver brake triple valve and located in the cab in easy 
reach of the engineer, the straight air brake and ET 
brake are much better. They are valuable aids in making 
smooth stops with freight trains at water plugs. 

93. Q. How does the air signal operate? If the air 
signal on the engine whistled each time you released the 
brakes, what would be the trouble? If the whistle blows 
frequently when not in use, what is the matter? If it 
blows one long blast? If the whistle is weak on engine 
will it usually help it to blow out the signal hose on the 
rear of tender? 

A. The air signal valve on the engine is operated by 
a reduction of pressure made in the signal line. This 
signal line is supplied with air from the main reservoir 
which passes through a reducing valve set at a much 
lower pressure than the standard braking pressure, so the 
operation of the brake will not interfere with the opera- 
tion of the signal. The opening through the reducing 
valve is choked down to restrict the flow of air into the 
signal pipe and allow a reduction to be made in its 
pressure. This reduction must be a sudden one, like an 
emergency reduction for the triple valve, or the reducing 
valve will feed air into the signal pipe as fast as it is 
taken out at the car discharge valve. When the pressure 
is reduced in the signal line at the car discharge valve 
and this reduction extends to the signal valve, it affects 
the pressure in chamber A above the diaphram 12 first, 
so that the pressure in B under the diaphram lifts it up, 
also raising the discharge valve 10 off the seat at 7, which 
allows the air to pass to whistle. 

If the diaphram gets bagged down, the pressure in B 



AIR SIGNAL DEFECTS 147 

will raise the baggy part of the rubber and valve will not 
raise off the seat. 

The stem of valve 10 has the sides flattened, except 
for a short distance at the top, where it enters bushing 9, 
when this stem rises the flattened part comes above bush- 
ing 9, and air from B also goes to the whistle, this 
reduces the pressure in B. When the car discharge valve 
is closed and the signal line pressure is increased by the 
reducing valve, as the stem of 10 makes a moderately 
close fit in the top of bushing 9, air passes into B slowly 
while recharging. Chamber A is therefore charged up 
first so diaphram is sure to set valve 10 promptly. 

If the fit of the stem at the top of the bushing is too 
loose the valve is liable to rise on its seat so the signal 
will "repeat" and give more than one blast for each pull 
of the car discharge valve. 

This fit must be exact or the signal valve will not 
always respond on both long and short trains to the 
proper reductions. 

If an air signal whistles each time brake is released 
with standard braking pressure, it is a sign the reducing 
valve is dirty and stuck open, so air goes back into main 
reservoir from signal line each time main reservoir press- 
ure is reduced in recharging train. In this case signal 
line has main reservoir pressure. Clean the reducing 
valve before the air signal hose bursts. The whistle will 
give a shrill sound if pressure is too high. If the spring 
in the old style reducing valve over diaphram is too stiff 
it will do this. The improved reducing valve is regulated 
for the proper pressure in the same manner as the feed 
valve on F-6 brake valve. The reducing valves are set at 
about forty-five now ; the old valves were set at twenty- 
five pounds. This is so as to carry a lower pressure in 
signal line than is used to operate the brake. To test 
the pressure at which reducing valve operates, shut off 
the pump, reduce the main reservoir about five pounds 
at a time through brake valve till the signal whistle blows ; 
this shows that the reducing valve is held open by the 



Signal Valve* 




Pressure Reducing Valve* 



Improved Reducing 
Valve* 



AIR SIGNAL DEFECTS 149 

spring so air can pass from signal pipe into main reser- 
voir. If the signal whistle blows frequently when not in 
use, there is a leak somewhere, which the jar of the 
engine may open for an instant, or the reducing valve 
may be out of order. If it sticks a little in its seat, as in 
cold weather, a very small leak will cause the whistle to 
give a strong blast — or a jar may unseat signal valve. 
When it blows one long whistle some of the valves on 
engine are stuck, or the car discharge valve is opened a 
second and third time before the whistle stops blowing 
the first blast; the pressure in signal line must equalize 
each time between the blasts to make it work accurately. 
If the stem 10 makes too close a fit in bushing 9 the 
whistle will give only one blast for two or more reduc- 
tions of signal line pressure, or a very small leak in the 
signal line will cause signal valve to operate at intervals, 
when a proper fit would allow it to work properly. If 
the whistle bell works loose so it does not make a clear 
sound, or is located near partly opened windows so a 
strong draft of air blows across it, when train is run- 
ning fast, the sound will be very weak. Blowing out 
the signal hose at rear of tender gives all the valves a 
chance to make a full opening and clean out the dirt. 
To test the signal line for leaks, shut the cut-out cock at 
the reducing valve; if the signal line leaks, the whistle 
will blow as soon as the leak reduces the pressure. On a 
double header both whistles should sound for the same 
reduction of signal line pressure. If they do not, close 
the cock in the reducing valve on the following engine 
so only one reducing valve will be feeding into the train 
signal line and thus allow the car discharge valve to do 
its work properly. With both reducing valves cut in the 
signal valve will not always operate on the leading 
engine when the brake pipe reduction is made from the 
rear cars of a long train. 

With the ET locomotive brake, the same reducing 
valve is used for the independent brake valve and the air 
signal system. There is a non-return check valve in the 



150 trainmen's questions 

signal pipe so the air can not get back from the signal pipe 
when the independent valve takes air to apply the brake 
as it would sound the whistle. This valve is shown at 
question 37. 



FOR TRAINMEN 

94. Q. When coupling the engine to an air brake 
train, equipped with quick-action triples and already 
charged with air, which angle cock should be opened first ? 

A. The one on engine always, so as to fill the hose 
from engine. If cock on car is opened first, the train 
brake is liable to set with emergency action. Get in the 
habit of opening the cock on engine first, whether train is 
charged or empty. 

95. Q. When coupling an empty car to other cars 
already charged and working, how should the angle cocks 
be opened? 

A. Open the one on empty car first, so the empty 
brake pipe and empty hose will be connected. Then open 
the angle cock on the charged car slowly so the pressure 
in brake pipe will not be reduced any faster than the 
engine, can supply it. This will prevent the brakes setting 
on head end of train, which they will do with emergency 
action if angle cock is opened suddenly. A little practice 
will teach you the advantage of this. This applies to 
coupling up the air on a train that has been separated to 
open public crossings. When coupling to cars on a side 
track that are going with your train, make the air brake 
connections also, so the auxiliaries will be charging ready 
for operating the brake while you are getting out on the 
main track, this will save time in testing the brakes, as 
they will be ready when train is all coupled up. When 
air braked cars are to be set on a coming train, charge 
these cars with air from the engine used to place them 
on the train, it saves delay. 

96. Q. If an angle cock at head end of train is only 



152 MAKING UP A TRAIN 

partly opened or there is an obstruction in the brake pipe, 
how will it affect the operation of the brake? 

A. The brake can be set with service application, but 
it releases very slowly as the air does not get back fast 
enough to move all the triple valves to release promptly, 
and any triples with defective packing rings back of the 
obstruction will be sure to stick. With angle cock on 
tender partly open, you cannot always get the emergency 
action of the brake. When passing over the top of the 
train, angle cocks can be inspected, as they are generally 
far enough outside the end of car so the handles are 
visible from top of car. When cocks are wide open the 
handles are exactly over the hose. The old style plug 
shut-off cocks come in the straight pipe just under the 
end of car and cannot be seen when passing over the cars. 

97. Q. Can an air brake train be made up so it will 
be impossible to get the emergency action of the brake 
from the engineer's brake valve? 

A. If there are four cars with the brakes cut out at 
cross-over near triples, or four cars with brake pipe only, 
or with plain triples, next to the engine, the reduction of 
air pressure in brake pipe will be so gradual on the fifth 
car that you cannot get the emergency application of the 
quick-action triples. It takes a sudden reduction at the 
first quick-action triple to get the emergency. Switch the 
plain triples among the quick-actions; you may need them 
to make a sudden stop in an emergency. 

981 Q. Why should train brakes be tested before 
leaving a terminal or any point where the make-up of the 
train has been changed? How should this test be made? 

A. So you will know before starting out that the 
brakes will work when necessary. After coupling the 
engine on the train the pressure should be equalized in all 
the auxiliaries, so all the brakes will set at the same 
reduction of brake pipe pressure. The pressure should be 
70 pounds in the auxiliaries in order to get a full applica- 
tion of the brakes to test the piston travel. While the 
engine is charging the train to standard pressure, which 



TESTING A TRAIN 153 

will take some time on a long train, a careful inspection 
should be made for leaks, and to see that all brake pipe 
cocks, cross-over cocks and pressure retainer handles, are 
in the proper position to operate all the brakes. When 
standard pressure is reached the brakes should be applied 
from the engine that is to handle them with a full service 
application made in the same manner as when making a 
station stop of the moving train. The trainmen or in- 
spector will then examine each brake to see that it is set 
with not less than five nor more than nine inches piston 
travel. When all brakes are inspected, if they are set 
properly, he will give a signal to the engineer to release 
brakes and examine each brake to see that they have 
released properly. If any brakes require adjustment of 
piston travel it must then be done. Be sure to close the 
cut-out cock in the cross-over while doing any work on 
the levers or shoes, so the brake will not set and injure 
the workman, opening it when adjustment is made. If 
pressure retainers are to be used, they should be tested 
after the piston travel is tested, by applying the brakes 
with a 10 pound reduction, with retainer handles turned 
up. As soon as the retainers are quiet, go along and turn 
down the handles, the air should blow out from each of 
them, which shows that they hold the pressure in cylinders. 
Long freight trains can be tested by two inspectors, one 
at each end working towards the middle of the train till 
they meet. On passenger trains equipped with the air 
signal, the signal for releasing after a test should be 
given with the car discharge valve from the rear plat- 
form of the last car. 

99. Q. How can the piston travel on a freight car 
be tested and then taken up the proper length when car 
is not charged with air and brake operated? 

A. See that the push rod going from piston to brake 
cylinder lever is clear in against the bottom of piston 
sleeve. Make a mark on the push rod even with the end 
of the sleeve. Set the brake by hand as tight as possible, 
with a club if necessary; the distance push rod is pulled 



154 DEFECTIVE BRAKE 

out of the sleeve is the piston travel. There is generally 
over an inch more piston travel when car is moving than 
when standing; it is more with heavy braking power on 
a car than with light. The piston travel on an empty 
car may be very short, say four inches, and when loaded 
the same car may have nine inches. When testing from 
the engine, have the brakes set with full service applica- 
tion, so you will get full piston travel. 

100. Q. If the brake sets tight when you are charging 
the auxiliary reservoir with air when first coupling the 
hose to another car, should you cut out that brake? 

A. If it is a quick-action triple it is a sign that air 
leaks through some of the joints or valves in the triple 
into the brake cylinder. Have the engineer set and release 
the brake suddenly, once or twice; if there is dirt on the 
rubber seat of the emergency valve which causes the 
trouble, it will sometimes blow it off; if it does not make 
the brake work all right, very likely some of the gaskets 
are leaking badly; in such a case cut it out and bleed it. 
With the freight brake there may be a leak in the pipe 
from the triple valve to the brake cylinder which passes 
through the auxiliary reservoir, nothing can be done on 
the road for a leak of this kind but cut out the brake. 
Most always in these cases the air blows out of exhaust 
port or at the pressure retaining valve. With the plain 
triple the plug cock in triple may be turned out for 
"straight air." This will allow the air to go direct from 
brake pipe to brake cylinder; none of it will come out of 
exhaust port, as the triple is cut out from brake pipe and 
cylinder. In this case cut it in for automatic. If the 
handle is gone, or put on wrong, examine the marks on 
the end of plug which show which way the' air openings 
are and you will know which way to turn the plug. If 
this plug cock leaks, the air can get past it from brake 
pipe to brake cylinder. If brake will not work after one 
or two applications, cut it out. With all plain triples the 
brake should be released first, although the plain triple 
used on freight equipment is built to bleed the brake 



PISTON TRAVEL 155 

cylinder when brake is cut out. Sometimes this bleed 
hole, which is in one side of plug cock in the plain freight 
triple valve, gets stopped up, in which case it may be 
necessary to let all the air out of the brake pipe — set 
this triple for straight air which will bleed brake cylinder, 
after which cock in triple can be placed in cut out 
position. 

101. Q. If the piston travel is too long or too short 
what effect does it have on the brake as to its holding 
power? 

A. If it is too short it will not cover the leakage 
groove, and air will leak out of cylinder; it must travel 
three inches to cover this groove. If it is too long it will 
strike the cylinder head, which will get the force instead 
of the brake shoes ; it must travel twelve' inches to do this. 
All brake pistons on coach, freight and tender equipment 
of standard gage have 12-inch piston stroke, but should 
not have over 8 or 9 inches piston travel. The piston 
travel should be adjusted equally so the braking power 
will be equal on all cars. Unequal piston travel gives 
unequal braking power. This is the cause of many severe 
shocks to long trains when first applying the brakes, an$ 
still more severe shocks when releasing the brakes at a 
slow speed. For instance, if some of the brakes have only 
five inches piston travel, when the engineer makes the 
first reduction of brake pipe pressure to apply the brakes, 
those with short travel will set hard enough to take up the 
slack of train quicker than the other brakes with long 
piston travel. A first reduction in applying the brakes is 
at least 7 pounds, less than this will not apply all the 
brakes on a long train. This will give a pressure of 
23 pounds on the piston with 5-inch travel, 8 pounds on 
one with 9 inches travel, one with 10 inches travel will 
not show any pressure at all, the shoes will just come 
nicely up to the wheels. A few short travel brakes can 
give serious shocks in a train that are plainly felt at the 
rear end. 



156 LEAKY PACKING LEATHER 

102. Q. If air blows past piston packing so freight 
brake leaks off, can it be fixed on the road? 

A. Sometimes this is from want of oil in the cylinder; 
if the oiling plug near back cylinder head where it makes 
a joint with cast iron auxiliary reservoir is taken out and 
four or five tablespoonsful of black oil put in, it will soften 
the packing so it will be tight. The piston sleeve should 
then be turned around one-half turn to bring the softened 
packing to the top of the cylinder. This should be 
attended to by car inspectors, but is not always done. In 
no case should oil or water be put in the hose and be 
blown back into the triple with the air. It will carry the 
dust and sand back in the pipe towards the triple; this 
stops up the strainers, and if any gets by the strainers it 
spoils the rubber seat of the emergency valve, and cuts 
the triple to pieces very fast. Putting oil in the hose will 
destroy the efficiency of the brake in very short time. 

103. Q. How can the air signal whistle be operated 
from the cars most successfully? 

A. By allowing just enough air to escape at the car 
discharge valve to reduce the air signal line pressure clear 
to signal valve on engine, so that it will operate promptly, 
then allowing car discharge valve to close and remain 
closed till signal line is recharged to standard pressure; 
this sometimes takes two seconds. A heavier reduction 
with a longer interval between pulls is needed for a very 
long train than a short one. The whistle will give only 
one blast if the car discharge valve is opened a second 
and third time before the whistle stops blowing the first 
time. 

If you make a second and third reduction before the 
reducing valve on engine has had time to charge signal 
line to standard pressure, the second and third blasts of 
whistle will be very weak; in cold weather the reducing 
valves do not always work perfectly. Sometimes when a 
car discharge valve is opened, a sufficient amount of air 
will seem to blow out there, but on account of an 
obstruction near the brake pipe Tee under car it does not 



AIR SIGNAL 157 

reduce the pressure enough at the engine to operate the 
signal valve, and the whistle cannot be operated from that 
car when it works from other cars. If the whistle blows 
once when engine is coupled to train and cannot be 
sounded afterward, look for a bad leak near rear end of 
train. 

If the whistle cannot be sounded from any cars back 
of a certain car, the cock in back end of that car is shut, 
or brake pipe is stopped up so you cannot make a sudden 
enough reduction there to affect the signal valve on the 
engine. If one blast of the whistle is used to start the 
train without using any additional signal, remember that 
one blast of the whistle can be given (without opening car 
discharge valve) when you do not want the train started. 
For instance, if the signal hose has been uncoupled (with- 
out the knowledge of the engineer) for any purpose; when 
the cock is opened enough air goes into empty hose to 
sound the whistle, giving signal to start the train before 
the man coupling hose can get out from between coach 
platforms. Other causes may cause the whistle to give 
one blast when not intended, therefore it is not always 
safe to use one blast of the whistle when standing still, 
to start the train. 

104. Q. If hand brakes are used on part air train, on 
which cars should they be used? 

A. On the cars next behind the air braked cars so the 
hand brakes will hold these cars and prevent slack run- 
ning out of rear cars when air brakes are released. In 
case of an emergency, all hand brakes should be set on 
cars that do not have air brakes working. Care should 
be taken that hand brakes are released on rear end of a 
part air train first, air brakes last, when running forward 
and in the reverse manner when backing a train. 

105. Q. On an air braked passenger train in case the 
engineer whistles for brakes what is the trainmen's duty? 

A. Open tthe conductor's valve first. An angle cock 
may be closed which prevents the engineer applying all 
the brakes. If the air escapes freely and the brake goes 



158 LEAKING BRAKES 

on, let hand brakes alone. If no air escapes from brake 
pipe the brake may have already been set. Try the hand 
brakes last, if the brake is set with air pressure you can 
not move it by hand on any cars where the hand brake 
sets opposite to the air brake. If it is not set with air 
you can set it by hand, the' air may have leaked out of 
cylinder. 

106. Q. How do leaks affect the operation of the 
brake on a car or coach? 

A. If the brake pipe leaks the brake will continue to 
set tighter after the first reduction till full set. Leaks at 
the gaskets in the couplings can be stopped by putting 
in new gaskets. Do not pound the guard arms of the 
couplings as that will likely cause the hose to tear off 
in a break-in-two. This leak affects a single car or a 
short train more than a long train, as a short brake pipe 
has less volume of air to leak out. 

A leak from the brake pipe past the seat of the emer- 
gency valve will allow the brake pipe air to equalize with 
the brake cylinder when the brake is applied so the triple 
slide valve has closed the exhaust port; this may stick 
this brake especially if the triple piston packing ring also 
leaks. 

Any leak from the auxiliary which makes that press- 
ure less than the brake pipe will move the triple to ex- 
haust position; the air in cylinder will escape through 
exhaust. With a leaky packing leather the air will blow 
past it, coming out around the piston rod or sleeve; none 
will come out of the exhaust. 

107. Q. Where should you look for the trouble if the 
brake applied properly, but would not release? 

A. Very likely the pressure retaining valve was 
closed; examine it first to be sure it is open. On some 
sleepers and official cars both the triple valve and re- 
tainer are concealed by the reservoirs and lockers, so it is 
necessary to hunt them up beginning with the triple 
exhaust, and if any pipe is attached following it up. If 
the retainer pipe is stopped up or plugged no air can come 



STICKING BRAKES 159 

out of triple exhaust. In cold weather the water from 
drip valves of steam heated cars may splash over the 
exhaust ports of triple valve and freeze on; this may 
stop up the exhaust. 

Levers or rods may catch on bolt heads or other pro- 
jections under the car and hold the brake after the air 
has exhausted from cylinder. If the release spring in 
cylinder is broken the piston will not move back. Stopped 
up strainers at the triple have been known to prevent 
release of brake; air would pass out of valve, but could 
not return quickly. 

108. Q. In case a brake is noticed to be sticking 
regularly, can you help it to release at the same time the 
others do? 

A. Short piston travel may cause this trouble. By 
extending the piston travel it will lower the auxiliary 
pressure on a full application so the triple is more likely 
to move up promptly. As brakes are more apt to stick on 
the rear of a long train than when next the engine, this 
car can be set ahead if necessary to use its brake. 

Leaky triple packing rings and choked strainers will 
also cause this trouble. Better cut out the brake than 
risk spoiling the wheels. Report this defect to the proper 
party. 

109. Q. How does the water raising system used on 
Pullman cars operate? 

A. This system has so many modifications and is so 
complicated that a full description cannot be given here. 
There is an air reservoir which is charged with the air up 
to brake pipe pressure, sometimes directly from the brake 
pipe; at other times from the brake auxiliary reservoir; 
the latest method being to take air from the brake aux- 
iliary. To regulate the flow of air into this air storage 
reservoir there is a governor and non-return check valve; 
the latest pattern of which is here shown. The governor 
operates exactly like an air pump governor and should 
be set at 60 pounds so it will not interfere with the air 
brake pressure when that is below 60 pounds. In this 



160 



WATER PRESSURE REGULATOR 



same valve is a non-return check 38, to prevent air 
coming back from the air storage reservoir, the stem of 
which is made a neat fit at h so the air will feed past 
it slowly and not take air too fast. Between the air 

Water,Pressure Governor 
Valve. 




TO AIR STORAG-e 
RESERVOIR 



storage reservoir and the water reservoirs is a reducing 
valve similar to the one used with the air signal, set at 
20 pounds, which pressure is sufficient to give a good flow 



WATER RAISING SYSTEM 161 

of water to the basins. If this reducing valve is set at 
too high a pressure or gets dirty or stuck open so it does 
not operate, the full pressure of the storage reservoir will 
be in the water tanks, which not only uses too much air, 
but is liable to splash the water all over the basins when 
faucet is opened. The pressure in the water tanks oper- 
ates this reducing valve. When the tanks are to be re- 
filled the air supply is shut off, that in the tanks is 
allowed to escape and water put in. When air comes out 
into the basins with the water it is a good sign the water 
is nearly gone. If no water or air comes out when you 
are sure there is a proper air pressure, examine the 
numerous cocks to see if any of them are closed. As 
the cars are not all piped exactly alike it is usually neces- 
sary to trace the pipes up and locate the stop cocks and 
valves when making an inspection. There are also heat- 
ing pipes connected with the devices of the water raising 
system to prevent freezing up. Gages are usually located 
up in the cars which show the air pressure in the storage 
reservoir and water tanks, 70 in the former after charging 
fully, and 20 in the water tanks. Suitable cocks under 
control of the porters are provided to open or close the 
passage of air from brake system to the water raising 
system with a code of rules for operating these cocks. 

110. Q. How does this water raising system affect the 
operation of the brake? 

A. When air is passing from brake pipe or auxiliary 
to air storage reservoir it takes a little time to charge 
the storage reservoir. If at that time brake is applied 
as when making a terminal test of train brakes, air pass- 
ing from the brake pipe will set the brakes tighter; if it 
-goes from the brake auxiliary it will likely release that 
brake, especially if set with a light application. If the 
non-return check valve leaks back after air storage reser- 
voir is fully charged, this air can flow in the brake pipe 
if so connected and release all the train brakes. If the 
connection is made to the brake auxiliary, a leaky check 
valve will allow the volume of the storage reservoir to 



162 WATER RAISING SYSTEM 

be added to that of the auxiliary and skid the wheels on 
a full application. If all the stop cocks are not properly 
operated and the valves in good order the work of the 
brake may be interfered with, which shows that it is 
absolutely necessary that they should be inspected at 
regular intervals by competent men and be maintained in 
proper order. If the governor which restricts the flow 
of air from the brake system is in perfect order and set 
at the proper pressure, unless a large amount of air is 
used by the water system, the operation of the brake 
will not be materially affected. If air is taken from the 
brake system during the application of the brake it is 
sure to affect the work of the triple valve, either to apply 
the brake harder or release it. 

The widespread use of this system requires that coach 
inspectors inform themselves as to its construction and 
operation, and that trainmen and porters comply strictly 
with the rules for its operation. 

111. Q. Can you get the emergency action of the 
brake with the pressure retainer holding 15 pounds? 

A. Yes; if the triple is in exhaust position, with brake 
pipe and auxiliary equalized at 70 pounds, when a sudden 
reduction of brake pipe pressure is made, it will move the 
triple piston full stroke, opening the emergency port. 
With air at 70 pounds pressure in auxiliary the emergency 
piston, having only 15 pounds pressure under it, will be 
forced down at once, the brake pipe air pressure will still 
be so much above 15 pounds that brake pipe air will flash 
into the brake cylinder, and this sudden reduction made 
by the triple will affect the next triple so it will work 
quick-action also. Question 50 explains why quick-action 
can not be had after a moderate service application. The 
use of retainers interferes so little with the quick-action 
that the emergency action will jump over as many cars 
with the brakes cut out at the cross-over cocks with all 
retainers holding 15 pounds as when retainers are not 
being used, provided the triple valve starts from exhaust 
position and auxiliary recharged to 70 pounds. 



THE HIGH SPEED BRAKE 

For ordinary speed, below thirty miles an hour, the 70 
pound automatic brake is able to control the train in the 
ordinary manner, but when the speed is much higher, 
more power is required in proportion as the speed is 
higher. It is the friction of the brake shoes on the wheels 
that arrests tthe speed of the train and finally brings it 
to a stop. In addition to arresting the momentum of the 
train this friction must also arrest the rotary motion of 
the wheels turning around at high speed; this takes con- 
siderable brake power. There is a difference in the 
amount of the friction of the same shoes and wheels at 
different speeds, it being greater at a low speed than at a 
high one. 

What is called the co-efficient of friction, which is the 
proportion between the brake power applied to the shoes 
and their holding power, is about .074 at sixty miles an 
hour, increasing to .241 as the speed is reduced to ten 
miles an hour, to .273 at five miles an hour and just as the 
final stop is made it is .330, so you see the brake shoes 
really hold less at a high speed than at a low one, and 
more brake power can be applied at the high speed than 
could be safely used at a low one and make the holding 
power about right for each speed. 

Now it follows that if the full brake power was the 
same for all speeds, if it was the proper power for a 
moderate speed it would be much too low for a high 
speed. If a high speed was the standard the full brake 
power would be too high for the low speed, the wheels 
would skid on the rail and a loss of about two-thirds of 
the brake power would result. This would allow the 
train to run considerable farther than if the wheels were 
held back by the shoes just up to the sliding point — 
without sliding. 

Therefore, an attachment to the brake that would give 
a very high brake power when first applied while running 
at a very high speed and gradually reduce this brake 



164 THE HIGH SPEED BRAKE 

power at about the same rate the speed was reduced, 
would be proper for all speeds. 

This brake power for moderate speeds has usually 
been fixed at 90 per cent of the weight of the coach 
when all the wheels have brake shoes applied to them, 
and is about all that can be used without sliding the 
wheels just as the final stop is made. 

This reduction of 10 per cent from the total load on 
the wheels with brake shoes applied is not exactly correct 
for both light and heavy cars. If 10 per cent of the 
weight of a car weighing 50,000 pounds is a proper 
reduction to prevent wheel sliding, then the same number 
of pounds reduction, i. e., 5,000 pounds should be enough 
for a car weighing 100,000 pounds. The old 90 per cent 
rule would give 10,000 pounds as the amount for this car, 
or 5,000 pounds more than needed. Therefore, to get 
the best service the same amount of reduction in pounds 
should be made from all cars braked to the same per 
cent. 

For emergency, the high speed brake will apply the 
brakes at first with a brake power of 125 per cent of the 
weight of the coach and gradually reduce the cylinder 
pressure as the speed is reduced, till it reaches the 
standard of 60 pounds, which gives a 90 per cent brake 
po.wer, at which point the reduction ceases, leaving the 
cylinder pressure at the amount and the braking power 
at the percentage at which the wheels will not slide when 
the car is about to stop. 

To get this increased brake power brake pipe and 
auxiliary pressure is . increased to 110 pounds. With an 
emergency application the pressure at first is about 85 
pounds. The brake cylinder pressure is reduced by an 
automatic reducing valve, which is here illustrated. 

This reducing valve, the latest pattern of which is 
shown in Fig. 1, is fastened by the bracket at x to the 
coach frame (see Fig. 6) and connected to the brake 
cylinder by suitable piping at z (see Fig. 2). When the 
air enters the cylinder at the time brake's are applied, it 



TO B*AK« 



HIGH SPEED BRAKE AUTOMATIC REDUCING VALVE 

TOR PASSENGER EQUIPMENT C\R3 AND UJCOMOTIVES. " 

Plate F 45, (1898 Pattern). 




Am<iuia«y St»W»W» 



Fifl.6 



166 



OPERATION OF REDUCING VALVE 



also comes in on top of piston 4. This piston is held up 
by the spring 11 against a pressure of 60 pounds per inch, 
if no more than 60 pounds conies into the cylinder the 
reducing valve remains stationary in the position shown 
in Fig. 3. 

It should be noted that the area of the reducing valve 
piston 4 that the brake cylinder air presses against is 
slightly less when the gasket 20 is up solid to the shoulder 
of the bushing e than after it is moved down. 

When a graduated service application is made, if the 
brake cylinder pressure raises above 60 pounds the piston 
4 is moved down far enough to open the triangular port 
b in the slide valve 8 to exhaust port a in the seat so 
that the widest part of port b is open as shown in Fig. 4. 
Air can then pass out of brake cylinder about as fast as 
it comes in through graduating valve of the triple ; when 




Fig 4. 

position of ports, 
service STOP 
Pressure Exceeding 60 Pounds 
in Brake Cylinder. 



brake cylinder pressure drops below 60 pounds the spring 
under piston 4 moves slide valve 8 up and laps ports a 
and bj as shown in Fig. 3, and no more air can escape. 
In case an emergency application is made the brake 
cylinder pressure rises like a flash up to 85 pounds, piston 



OPERATION OF REDUCING VALVE 167 

4 is forced down at once against the tension of the spring 
to the lower limit of its travel into the position shown 
in Fig. 5. This pulls slide valve 8 clear down, the small 
end of the triangular port b is open to port a, and brake 
cylinder air escapes slowly to atmosphere. As pressure 
is reduced spring 11 has power to move piston 4 up and 
the triangular port b opens wider, which reduces the 
brake cylinder pressure faster, down to 60 pounds ; at 
which point the slide valve is moved up to lap ports a 
and b so no more air can escape from brake cylinder ; 
this position is shown in Fig. 3. 

The size of this exhaust port b has been determined 
by experiments so as to reduce the brake cylinder pressure 
proportionate to the reduction in speed. It is a different 
size for each size of reducing valve to suit the different 
volumes of air which should pass out of small and large 
cylinders in about the same time. 

With a service application the reducing valve reduces 
the brake cylinder pressure only, as the triple valve closes 
the air port from the auxiliary. With an emergency 
application where the brake pipe pressure drops below 60 
pounds the triple holds the air port open and the reducing 
valve has to reduce both brake cylinder and auxiliary 
volumes to 60 pounds. 

When the brake is first set with emergency at a high 
speed the pressure is about 85 pounds in the cylinder; 
as the speed of the train is reduced by the action of the 
brakes, the pressure is also reduced by the reducing 
valve at about the same rate, till it reaches 60 pounds, 
where it remains till the brake is released in the regular 
way. 

After an emergency application the reducing valve 
lowers the cylinder pressure very slowly at first through 
the small pointed end of the port b, and faster as the 
pressure drops till it reaches 60 pounds, when the valve 
closes. The speed of the train is reduced by the action 
of the brakes slowly at first, and the reduction of speed 
is more marked each succeeding second of time till when 



168 OPERATING THE HIGH SPEED BRAKE 

nearly at a stop the speed is reduced very fast. The 
pressure is reduced at about the same ratio as the speed, 
so as to have it reach 60 pounds at about the time when 
60 pounds will do the work properly. 

This gives a very high brake power ready to use if 
found necessary at high speeds and still leaves the service 
application feature unchanged, ready for use in ordinary 
stops. With the service application the reducing valve 
remains in position as shown in Fig. 3. A reduction of 
20 pounds from 110 applies the brake fully, as this 
reduction will fill the brake cylinders at 50 pounds, the 
full pressure of an ordinary service application; as well 
as leaving a high auxiliary reservoir pressure of 90 pounds 
ready for two more full service applications of the brake 
if found necessary before re-charging; during these 
moderate service applications the reducing valve does 
not move. 

The brake pipe and auxiliary pressure is set at 110 
pounds with this type of brake — it may be more if the con- 
ditions seem to call for it. As the engines equipped for 
drawing these high speed braked trains may be used to 
draw coaches without the high speed attachments, some 
arrangement is needed for changing the standard brake 
pipe pressure from 110 pounds to the lower pressure and 
vice versa. For this purpose there are two feed valve 
attachments on the engine. One of them is* set at 70 
pounds, the other at 110, and there is a reversing cock 
between them which can be turned to cut-in either one 
for service as is desired, only one being operated at a 
time. This reversing cock and valves are coupled to the 
brake valve with suitable piping. The B-6 feed valve 
can be used instead of the reversing cock and two feed 
valves. There is a duplex governor for the air pump, 
one side of which is set for 90 pounds main reservoir 
pressure, for the ordinary 70 pounds brake pipe pressure, 
the other side set at the higher pressure required, and a 
cock to cut out the 90 pound side when using the higher 
pressure. Ten pounds excess has been found sufficient 



OPERATING THE HIGH SPEED BRAKE 169 

with a short train, but more is needed with a longer 
train ; in some cases 30 pounds, in order to be sure to 
release all brakes, after a light application. The tender 
is equipped with a quick-action triple and reducing valve 
the same as a coach. An engine truck brake is a neces- 
sary part of this equipment, which is supplied with air 
from the driver brake triple ; a reducing valve similar to 
the coaches is used, set at 50 pounds. Any extra coaches 
placed on these high speed braked trains require a reduc- 
ing valve, although a safety valve set to blow of! at 60 
pounds through a restricted opening can be used tem- 
porarily by screwing it into the oiling plug hole in the 
cylinder head. This safety valve is not as reliable as 
the reducing valve, and is only used as a temporary 
relief. 

This type of brake will stop a train running at sixty 
miles per hour in about 450 feet, less distance than the 
ordinary quick-action brake with 70 pounds. 

In making a graduated service application, with a 
pressure of 60 pounds in the brake cylinder, when a 
further service reduction of brake pipe pressure is made, 
the cylinder pressure will increase but slightly above 60 
pounds and immediately be reduced to that amount unless 
a full continuous service reduction is made, in which 
case the pressure may rise to 77 or 80 pounds, being 
soon reduced to 60 pounds by the reducing valve. After 
a cylinder pressure of 60 pounds is obtained, a full 
service reduction to below 60 pounds should never be 
made, except at high speeds in an emergency. 

A high speed brake train is handled in the same 
manner an expert engineer handles an ordinary passenger 
train of the same length. Remember 'that air at 110 
pounds pressure moves through the air ports more rapidly 
than at 70 pounds, so when listening to the sound of the 
air discharging from the preliminary and brake pipe 
exhausts watch the gage closely. To make the brake 
valve reduction more gradual a larger brake valve reser- 



170 HIGH SPEED BRAKE PRESSURES 

voir is now used, which holds about 812 cubic inches. 
The older ones hold close to 600 cubic inches. 

A 20 pound service reduction will give about the same 
brake cylinder pressure from 110 pounds that it does 
from 70, i. e., about 50 pounds. 

A 22 pound service reduction will give close to 60 
pounds in the cylinder, anything over that may be wasted, 
as the reducing valves will not let the cylinder pressure 
rise above 60 pounds. 

With 110 pounds on the back of the slide valve at the 
beginning of a service application and 90 pounds at the 
time of a release, the slide valve cannot be moved as 
easily ■ by the triple piston as when the pressures are 70 
and 50 pounds, and it will take more change of pressures 
each side of the triple piston to move it. 

Triple valves, when dirty, or when they need oiling, 
give more trouble with 110 pounds than with 70, on 
account of the increased pressure on the slide valve which 
makes them more apt to work quick-action with a gradual 
service reduction. For that reason both the triple valves 
and brake valve must be kept clean and well oiled and 
good stiff excess is needed with a long train. 

When coupling to a train having 110 pounds brake pipe 
pressure with an engine carrying 70 and 90 pounds, put 
the brake valve on lap and leave it there till the 110 
pounds pressure has blown down to 70 pounds and the 
reducing valves on the cars have blown down to 60 
pounds. Then with full excess go to full release and 
the brakes should all release. With L triples it is neces- 
sary to carry the high pressure on the engine to release 
the brakes. 

In handling any very long passenger train a straight 
air brake on the engine and tender is a valuable aid in 
preventing break-in-twos or serious shocks when releasing 
at a slow speed, the ET equipment on the* locomotive is 
still better. 

Unless an emergency arises requiring a very sudden 
stop, do not use the emergency application with 110 



USE OF EMERGENCY 171 

pounds, when running at a slow speed, say below twenty- 
five miles an hour. Unless the rail conditions are perfect 
the wheels are apt to slide ; this will increase the length 
of the stop. When an emergency, such as danger to life 
or property, confronts you, remember that all the brakes 
act quickly with the emergency application — in less than 
three seconds — which they will not do as quickly with a 
service application. Difference in piston travel does not 
affect the work of the high speed brake as much as it 
does the 70 pound brake with full service applications. 
As soon as the reducing valve operates it equalizes the 
cylinder pressures for long and short travels, for all will 
reduce to the same final pressures. If the leverage is 
proper, all cars will be braking alike. One of the best 
preventives of wheel sliding is equal and maximum brake 
power on all the cars, tender and engine. With all wheels 
holding back alike tests show that wheel sliding is rare. 



PLATE F.+8 



HIGH PRESSURE CONTROL 

With the heavy capacity cars now in general use, the 
empty weight of the car on which the braking power is 
calculated is such a small proportion of the full loaded 
weight that some provision must be made to increase the 
braking power on the loaded cars. This is particularly 
the case with coal and ore cars, which usually run empty 
to the mines and return loaded. For this class of cars a 
two-pressure system has been devised in which a moder- 
ately low pressure of 55 to 65 pounds is carried in the 
brake pipe and auxiliaries of the empties, 
while with the loaded trains 90 pounds 
can be carried and thus increase the brake 
power about 50 per cent. The duplex 
governor and reversing cock which is part 
of the High Speed Brake is used with the 
High Pressure Control, but the duplex 
governor is piped a little different. There 
are two separate pipes leading to the gov- 
ernor,, one from the main reservoir to the 
side of the governor set for the highest 
pressure, the other pipe leading from the 
left side of the reversing cock, which is 
set for the lowest pressure, to the low 
pressure side of the governor, so that when 
the low pressure feed valve is cut in, the low pressure 
governor is also cut in. 

When handling a train of empties going up hill the 
low pressure is used, coming down hill with a train of 
loads the high pressure is used, and thus the train can be 
controlled. Any empty cars in the train must have the 
air brake cut out at cross-over pipe when using the high 
pressure to avoid sliding wheels ; unless the caboose has 
a safety valve, it must be cut out also. 

A safety valve shown on this page is attached to the 
brake cylinders of the engine and tender. This same type 
of valve is also used on any extra coaches set in a High 
Speed Brake train. 




!k*"S 



SAFETY VALVE. 



THE AMERICAN AUTOMATIC SLACK ADJUSTER 173 










THE AMERICAN AUTOMATIC SLACK ADJUSTER 

The illustrations of the American Brake Co.'s Auto- 
matic Slack Adjuster show how the adjuster cylinder 
and adjusting screw is attached to the brake cylinder and 
dead cylinder lever. A small port is drilled and tapped 
in the brake cylinder at the point a, which is to be the 
limit of the running piston travel. A pipe e is connected 
from this port a to the adjuster cylinder at G. 

The brake piston acts as a valve to admit air to the 
adjuster cylinder. When it moves beyond port a during a 
brake application, air from behind brake piston passes 
out of port a through pipe e into the slack adjuster 
cylinder, pushes the piston to the left against the strength 
of the coiled spring, carrying the pawl out; the flat spring 
pushes the pawl down, hooking it down over a tooth of 
the ratchet nut. When the brake is released, air in the 
adjuster cylinder passes out, spring then returns the 
adjuster piston to its normal position which pulls back 
pawl; this rotates ratchet nut on the screw attached to 
the dead cylinder lever fulcrum jaw, moving the end of 
the lever up 1/32 of an inch, taking up some slack in the 
brake rigging. The slack is not taken up when the brake 
is applied, but after it is released, when there is no strain 
on the cylinder lever. When the coiled spring pushes 
back the piston and pulls the pawl, the lug strikes the 
stop, this raises the pawl out of the ratchet, so that the 
ratchet nut can be turned either way, if the adjuster 
piston is in normal position, this will allow nut to be 
turned by hand to let out or take up slack in brake rig- 



OPERATING THE SLACK ADJUSTER 175 

ging when new shoes are put on, or repairs made to brake 
gear. In case the ratchet nut is turned on its screw till 
the jaw is pulled up solid against the adjuster cylinder, 
in the older type, the pawl cannot be moved far enough 
by the spring to have the lug strike the stop; in which 
event the casing must be opened up and the pawl raised 
out of the ratchet nut, so it can be turned by hand. A 
later type of American Adjuster has a stop screw located 
near the adjuster cylinder, so arranged that the jaw comes 
in contact with it instead of the cylinder; by removing 
this screw and turning the ratchet by hand the pawl is 
released. A still later type has a tap bolt in the end of 
the the adjuster nut casing, slack off this tap bolt and the 
screw will turn a little more and release the pawl. The 
pawl and ratchet are enclosed in a tight case to keep out 
ice and foreign matter which would prevent their 
movement. 

In case the brake piston does not travel to port a the 
adjuster does not move any of its parts, but is at rest. If 
port a is partially or fully opened by the piston, which 
acts as a valve, compressed air is admitted to the adjuster 
cylinder, so it is operated. 

Slack adjusters take up the travel beyond a certain 
running travel limit. The brake piston will travel farther 
on a running car than one standing still, because the 
journals and bearings will be crowded to one side of the 
oil boxes and all lost motion that can be taken up in the 
truck comes out when running. For that reason the 
piston travel is usually found to be less when measured 
at a standing test than the actual distance of the port a 
from the pressure head of the cylinder. If this port a 
is eight inches from the head to allow eight inches travel 
it is not unusual to find the travel at a standing test, less 
than six inches. When locating port a first see how far 
the edge of the piston packing leather is from pressure 
head x. Port a is very small where it comes through the 
wall of the cylinder, so that the piston packing leather 
will not be cut when passing over the opening. 



176 TAKING UP THE SLACK 

The amount of slack depends on the brake leverage. 
For instance, a 10-inch brake cylinder has a power of 
4,700 pounds. If it is used on a coach weighing 52,220 
pounds, 90 per cent of this weight is 47,000 pounds, so 
the brake power required at the shoes is ten times that at 
the piston, or a total leverage of 10 to 1. With a car 
weighing 36,550 pounds the brake power would be 32,900 
or a total leverage of 7 to 1. Now with the same amount 
of slack on the shoes of each car one car would have 10 
inches piston travel, the other would have only 7 inches. 
With a leverage of over 10 to 1 you cannot restrict the 
piston travel to 6 inches and have the shoes clear the 
wheels so the coach will pull easy between the stations. 

One of the errors made when taking up slack by hand 
is using shoe clearance instead of piston travel as a guide. 
With a light car and large cylinder, where the total 
leverage is low, there will be considerable clearance in 
proportion to the piston travel. If the slack is taken 
up the same as for a car of heavy leverage, the brake 
piston will not pass over the leakage groove with mod- 
erate service applications. On the other hand, with a 
heavy car, the piston may bottom on the cylinder head. 
For this reason a device that will regulate the piston 
travel while the train is under way will do better work 
than hand regulation. 

Uniform piston travel is one of the prerequisites of 
good brake service. When this can be automatically main- 
tained during an entire trip it ensures a uniform as well 
as a maximum efficiency of the brakes. If this adjustment 
is made by hand the piston travel varies considerable on 
a long trip with a corresponding loss of efficiency. 

Unequal piston travel is the cause of a good many 
slid flat wheels in coach equipment, and is responsible for 
most of the break-in-twos in long freight trains. The 
braking power is increased by short travel and reduced 
by long travel, so that a coach with short travel may 
have power enough to slide the wheels when the other 
cars do not skid. 



BRAKE LEVERAGE 

Ability to figure up brake leverage is an accomplish- 
ment for an air brake operator — not always a necessity — 
it pays to know something definite about it. The rules 
are not complicated and formulas help to shorten the 
calculations. You should first learn how the several 
classes of levers operate and the difference between those 
of the first, second and third kind. A lever of the first 
land has the power applied at one end, the weight to be 
moved is at the other end and the fulcrum which takes 
"both the strain of the power and the resistance of the 
weight is in between the ends; in the cut of a lever of 
the first kind F is the force or power coming from the 
top rod, C in the middle is the fulcrum and W at the 
"bottom is the brake beam or weight to be moved. The 
cylinder lever connected to the brake piston is of the first 
kind. A pinch bar when we pry down on the rail and 
against the tire of a driving wheel is a good illustration 
•of this class of lever. 

A lever of the second kind has the power F applied at 
one end, the fulcrum C is at the other and the weight or 
"brake beam to be moved is between them at W ; the live 
lever of an outside hung brake is usually of the second 
kind. If you use the pinch bar by passing it under the 
object to be moved, resting one end on the ground and 
lifting up on the other it will show you the second kind. 

With a lever of the second kind the weight W takes 
as much strain as both the power F and fulcrum C. A 
lever of the third kind has the power F attached between 
the ends W and C; a lever of this class takes more power 
in proportion to the weight to be moved than either of the 
other kinds. With any class of lever the strains at the 
ends added together equal the strain in the middle. So 
you see the power developed by any one of three kinds of 
levers of the same length depends on the relative positions 
•of the power, weight and fulcrum. 

When you make measurements and calculations of 



CALCULATING BRAKE LEVERAGE 



179 



brake power, in case the pins or brake jaws are much 
worn set the brake by hand and measure the levers 
carefully as a mistake of a very short distance on the 
short end of a live lever will alter the power considerable. 
Always multiply the power or force in pounds by the 
distance in inches from the point F where power is 
attached to the fulcrum C, and divide this product by the 
distance in inches from fulcrum C to brake beam W. 




— FORMULA — 



F 



LEVER or LtKIND 



LEVER or2no KINO LEVER or 3rd KINS 



On page 177 is a small cut of the arrangement of 
levers for a coach brake with Hodge system which we 
will use to illustrate this explanation. 

Beginning at the brake cylinder where the power is 
first exerted, the pressure at F where the piston is 
attached to live cylinder lever is 4,700 pounds for a 10-inch 
cylinder with quick-action triple. This lever being of the 
first kind with fulcrum C between the ends, we multiply 
the power 4,700 by 12, the distance to the fulcrum C, and 



180 CALCULATING BRAKE LEVERAGE 

divide this product by 11 J A, the distance from the fulcrum 
to W, the Hodge lever rod connection, and have 4,900 
pounds strain on this rod which goes to the Hodge lever 
at X. This is a lever of the third class and being equally 
divided, each end gets half this power or 2,450 pounds, 
which is the force at the top end of the live truck lever. 
We next multiply 2,450 by the distance on this lever from 
F to C, 36 inches, and divide this product by 8, the distance 
from C to W, and we have 11,000 pounds, the strain on 
the brake beam. A shorter way is to multiply the pull 
at top end of live lever 2,450 pounds, by 4}^, the propor- 
tion of the live lever. To get the proportions of a live 
lever, divide the total length between the centers of out- 
side pin holes at F and C by the distance from C to W — 
called the short end — in this case 8 into 36 or 4*^ to 1. 
If the force at F is 2,450 pounds and the strain at W is 
11,000 pounds, the resistance at C will be 8,550 pounds, 
as the sum of the strains at both ends of a lever must 
balance the strain in the middle. This strain of 8,550 
pounds on the bottom rod goes to the bottom end of 
the dead truck lever at F and is to be multiplied by the 
distance from F to C — the outside length of dead lever — 
and the product divided by the distance from C at the top 
end of dead lever to W the brake beam connection; if the 
dead lever is the same proportion as the live one the 
result will be 11,000 pounds. 

Now going back to the cylinder levers, the tie rod has 
a strain of 9,600 pounds which is the sum of 4,700 and 
4,900, the strains on both ends of the live cylinder lever. 
This strain goes to the point F in the floating cylinder 
lever which is shown fulcrumed at C on the cylinder head 
and its free end W connected to the Hodge rod for the 
floating lever at the other end of the car and from there 
the power goes to the live and dead truck levers of the 
other truck as already explained. 

By this arrangement of levers we get a braking power 
on each end of the car equal on both trucks, with a total 
amounting to twice what the brake piston has; but we get 



CALCULATING BRAKE POWER 181 

it because the piston travels twice as far as it would if the 
fulcrum C in the live cylinder lever was fixed stationary; 
both cylinder levers move and the piston travels far 
enough for the two. 

Both cylinder levers need not be of the same length, 
but they must be of the same proportion if the same strain 
is to go to each end of the car. Coaches have cylinder 
levers exactly alike for each end of the coach; freight cars 
do not, although they are the same proportion. 

In making calculations for braking power for coach 
equipment, take 90 per cent of the weight which the 
wheels having brake shoes attached put on the rail under 
them. With all wheels braked this means 90 per cent of 
the weight of the coach when empty, a twelve wheel 
coach with only eight wheels braked takes 8/12 of the 
weight as a basis for calculation. Use 70 per cent of 
the light weight of any freight car used in interchange 
service ; while 100 per cent of the light weight, of a 
tender is generally used, a tender usually has a supply 
of water, fuel and tools which hold its weight up above 
the skidding point. The light weight of cars and coaches 
is used when making leverage calculations to keep the 
brake power below the limit at which the wheels will 
slide when the brake is operated on an empty car. If the 
brake cylinder receives its supply of air from the auxiliary 
only, as is the case with the plain triple valve and some 
of makes of quick-action triples, use 50 pounds as the 
equalized piston and auxiliary pressure. If part of the 
supply comes from the brake pipe, as is the case with 
the Westinghouse quick-action triple, use 60 pounds. 

Driver brake leverage is 75 per cent of the weight at 
the rail; an engine truck brake should have less than that, 
as there is no way to get sand to the rails for the truck 
wheels on slippery track. 



CAM DRIVER BRAKE LEVERAGE 

The limited space in this book will not allow a full 
description of how the cams and levers are designed, but 
some information on calculating their brake power will 
come handy to the men operating them. The illustration 
of the cam brake shows its various parts. 




CAM SC/f£tV PIN 



FORMULR. 



*-«* 



These cams are really segments of wheels with x-x for 
the centers. If they are properly laid out no matter how 
far they roll down, the point of contact at the edges of the 
wheels will always be on the line between the centers x-x. 

The cam as used with the brake is a bell crank with 
the long arm from g to x and the short arm from x to a. 
A true bell crank requires a fixed fulcrum at x to act as a 
brace to transmit the power at g to a, but in the case of 
the cams no fulcrum is needed there, for the faces of the 
cams rolling against each other act as fulcrums. 



CAM DRIVER BRAKE LEVERAGE 183 

To calculate the brake power, set the brake full on and 
measure the distance between the cam link pins at a-a. 
Also measure the distance between the cam link pins g-g 
and subtract this distance from the distance a-a; one-half 
of this remainder will be the long arm of the bell crank 
included in the design of each cam, which distance we will 
call X in the formula. We do not measure clear to the 
face of the cam, because the power is applied at g-g } 
one-half of the power exerted by the piston going to 
each cam. 

As the cams roll down against each other when the 
brake is set their faces touch at one point only, which we 
will call the point of "rolling contact." Place a straight 
edge from one of the cam screw pins at a t to the other, 
on a line with their centers and measure from the straight 
edge up to the point of rolling contact; this distance is the 
other arm of the bell crank, it is called the "offset," and 
is the distance from a to x also ; this is named O in the 
formula. This last distance divided into the length of the 
line from b to a — the long arm of the bell crank — gives 
the leverage of the cam. 

Multiply this leverage by 1,250 for an 8-inch cylinder 
or by 2,000 for a 10-inch cylinder, which will give the 
power delivered at the bottom end of the lever at a. 
Multiply this power by the whole length of the lever from 
a to k, called Z in the formula, and divide the product by 
the distance from the pin k to the pin i the brake shoe 
head, which is distance Y ; this quotient is the brake power 
delivered at that shoe; four times the power for one shoe 
will be the brake power for all shoes, which should be 75 
per cent of the weight on drivers. In all these calcula- 
tions we use 50 pounds as the air pressure per inch on 
the brake piston. 

To calculate the other way, take 75 per cent of the 
weight on the rail at the drivers, one-fourth of that will 
be the power required at each shoe. Multiply this amount 
by the length in inches of the lever from i to k and divide 



184 CAM DRIVER BRAKE LEVERAGE 

the product by the length from k to a; this last amount 
will be the power required at a, delivered by the cam. 

Divide this by 1,250 for an 8-inch cylinder or by 2,000 
for a 10-inch cylinder, the quotient will be the "leverage'' 
of the cam, and should correspond exactly with the. cam in 
use. To get the leverage of the cam, divide the length at 
X by the offset. 

The cams are designed to give the full brake power of 
75 per cent of the weight on drivers when the shoes and 
tire are worn down to their limit. The brake power 
increases as the length of the cam X is increased by wear 
of shoes and tires, but this does not affect the "offset" O. 
Therefore, with thick new tire and new shoes you will not 
get the full brake power, because the long lever of the bell 
crank in the cam is not the full length as laid out for a 
thin tire. To avoid the difficulty of having too much 
leverage with thin tire the radius of the face of the cam 
is struck from a point one and one- fourth inches further 
out than at x. A thick or thin shoe does not change the 
power as much where the cams are long with long wheel 
base as with very short cams. 

If you find that with a short piston travel, say two 
inches, the cams do not roll down so that their faces 
separate at the lower corners, as shown in the illustration, 
the cam links are too short. It is not unusual to find 
these links put up too short, and this defect reduces the 
brake power very materially. Changing the brake heads 
and putting on a wide one in the place of a narrow head 
also reduces the brake power, as it shortens the length of 
the cam. A thick shoe reduces the power the same way. 

In any brake the proportion between the piston travel 
and the brake shoe travel is the leverage. For instance, if 
the piston travel is four inches and the brake shoes travel 
one-half inch, the proportion is eight to one, so the power 
from the piston is multiplied eight times. If you can get 
the exact brake shoe travel of a brake and divide it into 
the piston travel you can easily rind the brake power. 




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CALCULATIONS FOR AIR PRESSURES 

To calculate at what finail pressure two separate 
volumes of air at different pressures will equalize when 
connected so air will flow from the higher to the lower 
pressure, it is necessary to reduce the volumes and press- 
ures to one standard of comparison. 

Suppose that a reservoir has a volume of 1,620 cubic 
inches with a gage pressure of 70 pounds per inch. If 
that same air was expanded to one pound gage pressure 
per inch it would occupy seventy times as much space or 
70x1,620, which is 113,400 cubic inches at one pound press- 
ure. We will call this amount cubic-inch-pounds, all 
volumes and pressures can be reduced to this standard. 

A gage shows the pressure above the atmospheric 
line, but absolute pressure begins at the vacuum line; to 
get absolute pressure we add fifteen pounds to the press- 
ure shown on the gage, before the calculations are made 
and subtract fifteen pounds from the result to get back 
to the gage pressure again. If the calculations refer to 
volumes which contain air at or above the atmospheric 
pressure, this fifteen pounds need not be taken into 
account. If any question of piston travel is connected with 
it, the fifteen pounds must be considered. 

We will take the case of a main reservoir of 16,000 
cubic inches at 90 pounds, and an empty brake pipe of 
twenty-five cars which have the same volume. Multiply 
main reservoir volume by its pressure and divide the 
product by the combined volume of both reservoir and 
brake pipe. 16,000x90=1,440,000 cubic-inch-pounds, this 
divided by 32,000 gives 45, the gage pressure at equaliza- 
tion. 

Suppose this brake pipe instead of being empty has 40 
pounds gage pressure in it, and the main reservoir 90; 
40 pounds in the brake pipe will be 640,000 cubic-inch- 
pounds, this added to the amount in the reservoir and 
the sum divided by the combined volumes will give sixty- 
five as the pressure at equalization. 



CALCULATIONS FOR AIR PRESSURES 187 

A retaining valve is holding 15 pounds in the brake 
cylinder. After charging the auxiliary to 70 another full 
application is made, we can figure the equalizing pressure 
as follows : 450 cubic inches at 15 pounds is 6,750 cubic- 
inch-pounds. The auxiliary at 70 holds 113,400 cubic- 
inch-pounds, the total amount in both is 120,150 cubic- 
inch-pounds, which now expands into the total volume of 
1,620 plus 450 or 2,070 cubic inches. Divide the full 
amount of air by the total space and we have 58 pounds. 
We do not figure from the vacuum line in this case. 

When calculating the pressure at which the brake 
cylinder and auxiliary will equalize when the piston moves 
out, remember that there is no atmospheric air in the 
space left by the piston in moving out and this space must 
be filled with air from the vacuum line of absolute press- 
ure, so we must add 15 pounds to the gage pressure of 
70 pounds, which gives 85 pounds. 

The auxiliary holds about 1,620 cubic inches at 85 
pounds, this is 137,700 cubic-inch-pounds absolute pressure. 
The volume of an 8-inch brake cylinder with 8 inches 
travel, including clearance and piping from the triple, is 
close to 450 cubic inches ; the combined volume is 2,070 
cubic inches. Divide 137,700 by this combined volume 
and subtract fifteen from the quotient, you will then have 
the equalizing pressure, about 51.5 pounds. 

To find how much brake cylinder air at 60 pounds 
comes from the brake pipe with an emergency application 
and how much from the auxiliary, proceed as follows: 
The brake cylinder volume of 450 cubic inches at 75 
pounds absolute pressure is 33,750 cubic-inch-pounds. The 
auxiliary of 1,620 cubic inches loses 10 pounds, from 
70 down to 60; this is 16,200 cubic-inch-pounds from the 
auxiliary; this subtracted from 33,750 leaves 17,550 cubic 
pounds to come from the brake pipe. Divide 17,550 by the 
volume 450 cubic inches we have 39 pounds absolute press- 
ure; subtracting 15 pounds to get gage pressure we have 
24 pounds as the part the brake pipe supplies; this varies 



188 PRESSURE WITH PARTIAL APPLICATION 

with the piston travel and condition of strainers, it is 
usually less than this. 

When you make a partial application of the brake and 
want to know what brake cylinder pressure will result 
from any certain reduction in the auxiliary, proceed as 
follows : Say we make a 10 pound reduction. If the 
volume of the auxiliary is 1,620 cubic inches, at 10 pounds 
per inch the total amount passing from the auxiliary to 
the brake cylinder would be 16,200 cubic-inch-pounds. In 
this calculation we will allow for the air contained in the 
clearance space of the cylinder, the auxiliary tube between 
the triple valve and cylinder, and the triple valve itself, 
which amounts to an average of 47.92 cubic inches, which 
contains air at 15 pounds per inch or close to 718 cubic- 
inch-pounds. This added to the amount coming in from 
the auxiliary makes 16,918 cubic-inch-pounds, and it will 
equalize in the 450 cubic inches total volume of the brake 
cylinder and clearance at 38 pounds absolute pressure, or 
23 pounds gage pressure. You can calculate for any given 
reduction the same way from any pressure; just as long 
as you do not make a brake pipe reduction that will cause 
the brake cylinder and auxiliary to equalize, or when you 
do that it stops the auxiliary reduction. A 10 pound 
reduction from 90 gives just the same pressure as at any 
lower pressure till you reach the equalizing pressure, 
which is usually below 50. The next 10 pound reduction 
from the auxiliary into this cylinder of air having a 
pressure of 23 pounds will show a greater proportionate 
raise on the gage, for the first reduction had to fill the 
cylinder from the vacuum line up to gage pressure — 15 
pounds — the second one had this work done for it, and 
therefore made a better showing on the gage. 

When making tests the gage will not always show 
these exact amounts, as the leakage groove uses consider- 
able air, auxiliaries are not all the size specified, the clear- 
ance in the end of cylinder varies, and the expansion of 
air lowers the temperature, which alters the pressure. 

The question of the fall of temperature is not taken 



SIZE OF RESERVOIRS 189 

into consideration in these calculations, as the temperature 
of the air in the brake equipment on a car is very close 
to that of the atmosphere at all times. 

To get the area of the piston, multiply the diameter by 
itself and that product by .7854. To get the volume of the 
cylinder, multiply this area by the piston travel and add 
the clearance. This clearance consists of the space between 
piston and pressure head, usually Y% of an inch, the pipe 
between the triple and the cylinder and the space in the 
triple valve that is filled with brake cylinder air. 

Reservoirs are so constructed that it is difficult to cal- 
culate their exact volume from their outside dimensions, 
this can be obtained exactly by weighing them while 
empty, then filling full of water and weighing again; the 
difference in weight will be the amount of water contained. 
A pound of water at 62 degrees occupies 27.71 cubic 
inches ; one cubic foot weighs 62.355 pounds. 

A cast iron auxiliary for an 8-inch freight brake holds 
about 1,620 cubic inches. 

10 x 24 in. wrought iron auxiliary 1.510 cubic in. 

12 x 33 in. wrought iron auxiliary 3.030 cubic in. 

14 x 33 in. wrought iron auxiliary 4.120 cubic in. 

16 x 33 in. wrought iron auxiliary 5.322 cubic in. 

The equalizing reservoir from 590 to 621 cu. in. the 
later pattern 10 x 14^4 inches long, hold 800 cu. in. A 
freight car has about 640 cu. in. in the brake pipe, hose, 
cross-over pipe and triple valve to the bottom of the 
triple piston — all this space contains brake pipe air. 

Main reservoirs vary in size to suit their location on 
the engine, when of sufficient volume there are usually 
more than one, having the air from the pump passing 
into the first one, from there to the next, and so on to the 
brake valve. This gives the air a chance to cool down to 
the normal temperature of the atmosphere, when it will 
deposit all its moisture as water in the main reservoir. If 
the air passes through the brake valve without cooling 
down it will leave some of the water in the brake pipe — 



190 TEMPERATURE OF AIR DURING COMPRESSION 

see question 8 — and give trouble in the operation of the 
brake. 

Main reservoirs should have a volume of at least 
20,000 cubic inches. Freight engines should have 1,000 
cubic inches capacity for each car in the train. An engine 
that can handle a 75-car train should have 75,000 cubic 
inches. Large main reservoir capacity is necessary to 
promptly release all brakes on a long train and will in a 
measure prevent stuck brakes and slid flat wheels on the 
rear cars — see question 9. A large main reservoir also 
tends to save a pump, as it can run at a slower speed, for 
it can run continuously, not intermittently. 

When air at a temperature of 60 degrees is compressed 
from the atmosphere line up to a gage pressure of 70 
pounds the temperature rises to about 400 degrees; with a 
pressure of 90 pounds it is about 450 degrees, at 105 
pounds it is 490 degrees. As this heat is the result of the 
mechanical energy of the steam developed through the air 
pump, you can readily see that it takes more power from 
the boiler to reach a high pressure than a moderate one. 
Also the air piston will come nearer the end of its stroke 
before the air is compressed to 105 than at 90 pounds, so 
that a less amount of 105-pound air is delivered than of 
90. As the air usually cools off to the normal tempera- 
ture before it passes into the brake cylinder, we can take 
no advantage of any expansion of air by the heat of 
compression. 

The heat that is given out by compression is taken up 
when the air is allowed to expand. When air expands 
through any opening from a high to a low pressure it 
takes up or absorbs heat from all surrounding bodies, this 
accounts for its being so cool when coming out of the 
bleed cock, exhaust port of a triple or exhaust pipe of an 
engine run by compressed air, in some cases it will form 
ice. 

When studying the equalizing processes in the opera- 
tion of compressed air equipment, remember that it is air 
that flows from one part of the equipment to another and 



THE NEW YORK AIR BRAKE 191 

not pressure. Pressure is a condition, air is a substance 
or material. When air flows from the auxiliary to the 
cylinder it will change the conditions or pressure in these 
places, but the pressure does not flow either way. 

It will take away much of the mystery of equalization 
if you bear these facts in mind. 



THE NEW YORK AIR BRAKE 

The important parts of the New York Air Brake that 
differ from those of the Westinghouse Automatic Brake, 
are the Duplex Air Pump ; Governor ; Engineer's Valves ; 
Compensating Valve; Quick- Action Triple Valve; Air 
Signal Valve and Brake Pipe Strainer. The Brake Cylin- 
ders and pistons in all their details; Reservoirs, both main 
and auxiliary; Pressure Retaining Valves; Reducing Valve 
for the air signal system; Brake Pipe with Hose Coup- 
lings, Angle and Cut-out Cocks and Conductor's Valves 
are the same in both systems of equipment; their con- 
struction and operation have already been described in 
this book. 

As freight cars in interchange service are moved from 
one railroad to another when of the same gage, there 
will be in all freight trains some cars equipped with the 
Westinghouse and others with the New York brake. The 
Master Car Builders' specifications require that all brakes 
in a train shall be so constructed that the different kinds 
will operate in unison, so as to control the speed of the 
train without shocks. For that reason the general rules 
for the handling of trains are the same, whichever brake 
is used. There are several differences in the construction 
of these two kinds of brake equipment, that give different 
results when they are operated; these points will be 
explained later on. 




(Goverhor) 



rPIPE 

FROM BOILER 



2DP55II 



2DPI38 



2DP59A 



m IX* PIPE 

TO EXHAUST 



2DP58A 
5DPI43 
2 DP 142 
2DPI4Q 



THE DUPLEX AIR PUMP 

This pump has two steam cylinders, 1 and 2, and two 
air cylinders, 3 and 4 ; the steam valves, 5 and 6, being 
operated by reversing or tappet rods, 8-8. These tappet 
rods are operated by the tappet plates 20, which are 
securely fastened to the lower side of each steam piston 
by bolts 55. The steam cylinders each receive steam from 
the boiler and exhaust to the atmosphere, the air cylinders 
each receive free air from the atmosphere; but the air 
in cylinder 4 when compressed passes into cylinder 3 and 
from there is forced into the main reservoir. Thus, the 
air cylinders compound the air, while the steam cylinders 
work simple. Each steam cylinder of the No. 2 pump is 
7 inches in diameter and 9 inches stroke, the low pressure 
air cylinder 4 is 10 inches in diameter, the high pressure 
air cylinder 3 is 7 inches in diameter; both cylinders have 
the same stroke as the steam cylinders, 9 inches. The 
volume of air cylinder 4 is twice that of cylinder 3. 

The sectional view shows the pump with all parts in 
the position when making its first stroke after turning on 
steam, steam piston 21 and air piston 32 which are con- 
nected by piston rod 18, having made a little over half 
their up stroke. At the bottom is shown the new style of 
main steam valve, a piston valve instead of a slide valve. 

Live steam comes from the boiler through the steam 
pipe and governor and into steam head 19 and passes 
into each steam chest around steam valves 5 and 6. This 
steam passage is shown by dotted lines from 56 on each 
side of number 19. A drain cock, 54, is tapped into this 
passage to allow condensed water to be blown out when 
first starting up the pump, at all other times while the 
pump is running it should be closed. The exhaust passage 
is shown leading from exhaust cavities of the slide valves 
5 and 6 through 58. Under 58 comes the drain cock for 
the exhaust; unless the pump sets high enough so all con- 
densed water will drain to the smoke arch end, this cock 
can be left open if so desired, providing there is a drip 



194 OPERATION OF DUPLEX PUMP 

pipe leading to the ash pan. The steam head is made 
with right and left side connections for live and exhaust 
steam, the openings not used are closed with threaded 
plugs. 

When steam is shut off from the pump, there being no 
pressure on the back of the valves 5 and .6, they drop to 
their lowest position as shown. Live steam when first 
turned on passes up through port 23-24 into cylinder 1, 
and if piston 22 is not already at the bottom of its cylinder 
1, it is forced down and held there. At the same time live 
steam passes through port 26 under piston 21, forcing it 
and air piston 32 upwards; air in cylinder 4 above piston 
32 raises valve 11 and passes into upper end of high 
pressure air cylinder 3 above piston 31. At the same time 
while piston 32 is moving up, free air from outside raises 
inlet valve 10, passing into lower end of low-pressure 
cylinder 4 and filling it ready for compression on down 
stroke of its piston. Piston 21 then remains at top of its 
stroke till the other steam piston makes an up stroke. 

When steam piston 21 approaches the top limit of its 
stroke, tappet plate 20 catches the button on the top end of 
the reversing or tappet rod 8, drawing this rod and slide 
valve 6 up so that port 27 is uncovered to the live steam 
and port 23-24-25 is connected to the exhaust. With live 
steam passing under it and the upper side connected to the 
exhaust, piston 22 moves upward, carrying air piston 31 
with it and forcing the air in upper end of the high-press- 
ure cylinder past the final discharge valve 13 into the 
main reservoir. At the same time, air from the atmos- 
phere flows in past valves 10 and 12, filling the lower 
end of the high-pressure cylinder 3 with free air. The 
low-pressure air cylinder has one inlet valve for each end, 
9 and 10; the high-pressure air cylinder has to draw its 
supply of free air through two inlet valves at each end, 
9 and 11 at the top end and 10 and 12 at the bottom. 
Valves 11 and 12 are the discharge valves for the low- 
pressure cylinder; 13 and 14 are the final discharge valves 
from the high-pressure cylinder to the main reservoir. 



OPERATION OF DUPLEX PUMP 195 

As piston 22 nears the end of its up stroke, the tappet 
plate moves rod 8 up, drawing valve 5 upwards, this con- 
nects port 26 with the exhaust so that the steam in 
cylinder 2 under piston 21 will pass out; port 28-29-30 is 
opened and live steam passes in above piston 21, forcing 
it down, bringing air piston 32 with it and compressing 
the air in the lower end of cylinder 4 past valve 12 into 
the lower end of high-pressure cylinder 3, and drawing 
a supply of free air past valve 9 into the upper end of 
cylinder 4. During this downward movement of piston 
21, piston 22 is stationary at the top of its stroke. As 
piston 21 nears the bottom limit of its stroke, tappet plate 
20 strikes the shoulder on rod 8, moving it and steam 
valve 6 to their lower position; this opens port 23-24 to 
live steam and 27 to the exhaust; steam piston 22 then is 
forced down, bringing air piston 31 with it; the air in the 
lower end of cylinder 3 is forced past final discharge 
valve 14 to the main reservoir, free air from the atmos- 
phere passes by valves 9 and 11 and fills the upper end 
of cylinder 3. This completes a round trip of both steam 
and air pistons. 

By means of the tappet rod each steam piston moves 
the steam valve that opens and closes the steam and 
exhaust ports for the other cylinder, so that when one 
steam piston completes its stroke it has moved the steam 
valve to operate the other steam piston and then remains 
at the end of its stroke while the other piston makes one. 
This ensures that the air pistons make a full stroke and 
leave no clearance space at the ends of the air cylinders, 
except the volume of the passages to the discharge valves 
and leaves the air pistons in the proper position so the 
air from the low-pressure cylinder can pass into the high- 
pressure cylinder ready for the final compression to the 
main reservoir. All the air valves have a lift of 1/16 
of an inch. Oil cups 54 are in the top heads of each 
air cylinder. 

The No. 6 Duplex Pump here shown has the steam 
end constructed in much the same manner as the No. 2 



NO. 6 DUPLEX AIR PUMP. 



ALL AIR VALVES f^L-53 53 ~ 

|/2"DIAM. J-j" LI FT L-.^T 

4A +B 




EXHAUST 



XPf/7/*t 



DUPLEX PUMP 197 

Duplex Pump. The air inlet and discharge valves are 
placed in another manner, the No. 6 pump has a separate 
air inlet for each cylinder to take in atmospheric air, their 
location is shown in the cuts of the top end of the pump 
and the sectional view. The bore and stroke of each 
cylinder is shown in the cuts as well as the course of the 
steam and air by the arrows, during the first up stroke. A 
description of the No. 6 is not necessary here, as with the 
description of the No. 2 pump and the illustrations, the 
operation of the pump can be readily understood. The 
low-pressure cylinder takes in air from the atmosphere 
at each stroke of its piston 32 and delivers the compressed 
air to the high-pressure cylinder through the intermediate 
valves 11 and 12. At each stroke of the high-pressure 
piston 31 it takes in a supply of air from the atmosphere 
through its inlet valves 15 or 16 and afterwards receives 
the air from the low-pressure cylinder in addition to the 
free air taken in. The defects of this pump are treated 
in the same manner as those of the No. 2. Leaks at the 
inlet valves are more easily located with the No. 6 than 
the No. 2, as there is a separate strainer for each inlet 
with the No. 6. 



DEFECTS OF THE DUPLEX PUMP 

When the Duplex pump stops, first open drain cock 54, 
if steam blows out strong the governor is all right. If 
very little steam passes out, examine the governor. If the 
button breaks off tappet rod 8, or tappet plate 20 gets 
worn badly or very loose, the steam piston on that side 
will make its up stroke, but the slide valve will not be 
raised up to open and close the steam and exhaust ports 
for the other cylinder. If the tappet rod is broken on the 
high-pressure side, both air pistons will stop at the top 
of their stroke; if the tappet rod is disabled on the low- 
pressure side, piston 21 can move to the top of its stroke, 
but valve 6 will not be moved up, steam will hold piston 



198 DUPLEX PUMP DEFECTS 

22 and air piston 31 at the bottom of their strokes. 
Taking off cap nuts 15 will soon locate which tappet rod 
is at fault. To locate at which end of the stroke the air 
piston has stopped, remove the oil cups from the top of 
air cylinders and run a piece of wire down to the piston. 
If the nuts 74 work loose and strike the top head so the 
piston can not make a full stroke, the steam valve on that 
side will not be moved to change the course of steam to 
the other cylinder, and the other piston will not move. 
This defect acts like a button broken off; it can be 
located by taking top head 47 off. 

Worn air piston packing rings will allow the pump to 
run very fast and not make much air ; it will run hotter 
than usual and pound badly. The air cushion necessary 
to keep the air pistons from striking the heads will be 
lost; this will cause the pound. Leakage of air around 
the high-pressure piston rod will waste the air already 
compressed, and allow the piston to strike the lower head; 
it will also make the strokes uneven. To locate worn 
air piston packing rings, run the pump very slowly against 
full pressure in the main reservoir. If the rings leak con- 
siderable, compressed air will get past the piston in the 
latter part of its stroke; this will reduce to nothing the 
amount of free air drawn in at the inlet valves. To 
locate the defective piston, note which one in making its 
stroke is not drawing in air properly. This is not a very 
good test for the high-pressure piston, as it may be draw- 
ing part of its supply from the low-pressure cylinder, 
which has been expanded by the heat of the cylinder. If 
the pump works all right at a low air pressure, and as the 
pressure increases the low-pressure cylinder seems to be 
doing most of the work, examine the high-pressure side 
to see why it is not doing its share. The low-pressure 
piston ordinarily works against a pressure of three 
atmospheres — 30 pounds gage pressure, which is the press- 
ure on the high-pressure piston at the beginning of its 
stroke when both cylinders have filled full of free air from 
the atmosphere. 



DUPLEX PUMP DEFECTS 199 

If an inlet or receiving valve 9 or 10 leaks, the air 
will blow out past it as piston 32 moves towards it. Both 
valves 9-11 or 10-12 will have to leak if any air gets 
back to the atmosphere from the high-pressure cylinder. 
Open the ojl cup on the low-pressure cylinder, run the 
pump slowly against the full reservoir pressure ; if valve 
11 leaks when the high-pressure piston is moving up air 
will pass valve 11 and blow out of the oil cup. If final 
discharge valve 13 leaks, stop the pump, opening the oil 
cup on the high-pressure cylinder will show it. If valve 
14 leaks, the piston, if not at the top of cylinder 3, will 
move up there unless the air can blow out around the 
piston rod. Leaky air inlet valves will cause the pump 
to make irregular strokes, quick towards the leaky valve 
and slow away from them. If discharge valves leak, the 
piston will move slowly towards the leaky valve and 
quickly away from it. A leak by the gasket 48 will show 
like a leaky air valve; to be sure which it is, the best way 
is to take up head 47 and examine the gasket and air 
valves. When the air valves or their seats have worn so 
as to materially increase the lift or allow them to leak, 
it is best to put in new valves and seats that are in perfect 
order. When new valves are placed in the old seats or the 
old valves ground in to a fit, be careful that the lower 
end of the wings of the valve does not strike on the 
cages or the stops of the valves under them. 

The exhausts from the pump when run very slowly 
against standard pressure, will usually show where the 
air leaks are located. 

Leaky steam piston packing rings will cause an inter- 
mittent blow. Run the pump slowly against full air 
pressure, open the drain cock in the exhaust at 58; you 
can soon locate the defect. A leaky steam valve will 
usually give a steady blow. 

Steam escaping at the piston rod packing is liable to 
be drawn in at the air inlet valves, and fill the equipment 
with water; this is very dangerous in cold weather. 



THE PUMP GOVERNOR 

The New York Air Brake Co. make three styles of 
governors: the Single, Duplex and Triplex. As these 
only vary in the number of air diaphram bodies attached 
to a single steam valve body, we will describe the Duplex 
governor, which is the one most generally used. Air 
enters the governor at e from the brake pipe to one 
diaphram body and from the main reservoir to the other 
diaphram body. At f is a strainer to prevent dirt or grit 

Duplex Governor. 

PLATE Q 8. 




yfigL t 





passing from e into chamber A. Air passes into the 
chamber A under the corrugated diaphram 13, which is 
held down on its seat 14 by a regulating spring 10, acting 
on the diaphram button 12. When the air pressure under 



OPERATION OF PUMP GOVERNOR 201 

the diaphram exceeds the resistance of the spring 10, 
the diaphram is raised off its seat on 14, this allows air 
at the brake pipe pressure to pass down through a and 
C into B on top of piston 4, which at once moves down, 
also moving steam valve 5 down against its seat and shut- 
ting off the supply of steam from the boiler to the pump. 
A small hole at o lets a little steam pass through to the 
pump so it will make a stroke at intervals. A vent port 
V in the cylinder 1 over piston 4 allows air to blow out 
steadily while the air pressure is operating the governor, 
this also tends to keep the pump moving. When the air 
pressure drops so that spring 10 can hold diaphram 13 
on its seat, the air escapes from chamber B over piston 

4 through vent V ; valve 5 and piston 4 are raised by the 
steam pressure and the steam again passes to the pump. 
When valve 5 is at the top of its travel a steam tight 
seat is at S, so no steam can work up under the piston 4. 
The dotted lines at x show the location of the drip open- 
ing in the side of the cylinder 1, which allows any steam 
that works up past valve 5 or air that comes down by 
packing ring 24 to escape to the atmosphere. When valve 

5 is partly open, steam can blow out at the drip steadily 
as its stem does not make a steam tight fit in the guide 6. 
The regulating springs over the air diaphrams are adjusted 
by the small adjusting screw 8 and fastened by the jam 
nut 9. 

The later pattern of governors have a large adjusting 
nut, it is shown in the Duplex Controller. 

The single governor is usually set at 70 pounds, as it 
controls the brake pipe pressure and is piped to passage 
E in the brake valve on the brake pipe side of the excess 
pressure valve 97. 

The Duplex governor has the low-pressure air dia- 
phram chamber connected to the brake pipe or chamber A 
of the brake valve, the opening into E of the brake valve 
must be plugged, and main reservoir air to the high- 
pressure side. The brake pipe side is set at 70 pounds 
and the main reservoir side at 90. With this arrangement, 



202 PIPING THE GOVERNOR 

if the governor diaphrams are not set for the proper 
pressures, the brake pipe pressures in running and full 
release positions will not be right. 

With the Double Pressure system, where a low brake 
pipe pressure is carried with empty cars and a higher one 
with loaded cars, both sides of the duplex governor are 
piped to the opening E. In the pipe leading to the low- 
pressure side of the governor there is a cut-out cock, 
when this is shut the higher brake pipe pressure will be 
carried. 

With the Triplex governor one air diaphram is con- 
nected to the brake pipe and set at one standard pressure, 
the second diaphram is set for a higher brake pipe press- 
ure, and the third diaphram is connected to the main 
reservoir air and set at the pressure desired there. There 
is a cut-out cock in the air pipe leading to the lowest 
brake pipe diaphram, which can be closed when necessary 
to carry a higher brake pipe pressure; this cuts the lowest 
one out of service. The diaphram 13 gets gummed up on 
the seat of 14 so that in some cases air leaks by it and the 
governor piston is operated before the proper pressure is 
reached. Or it may .get gummed up so much that air 
can not pass down to the piston. For defects common 
to governors, see front of book. 



THE 1902 MODEL BRAKE VALVE 

The duty of the brake valve is to control the passage of 
air from the main reservoir to the brake pipe ; from the 
brake pipe to the atmosphere or stop the flow of air 
through it in any direction. The engineer's brake valve, 
when in full release position, should allow the main 
reservoir air to flow directly to the brake pipe through 
large ports to equalize these pressures quickly. It should 
allow the air to pass through smaller openings in running 
position and maintain a higher pressure in the main 
reservoir after the brake pipe pressure has reached a 
standard amount. It should have a moderate opening 



Engineer's Brake VaJve. 
1902 MODEL, ^ 

„ TO ( ti"~'0% 

GOVERNOR jV %=M j \ 

FACE OF SLIDE VALVE 



K- -> 



CF 



Rf-M 



Supplementary Re&ervoir 

rfTT^-- Z LD 



0\P 



© \ (o \ 



o 



E? 



ra^s- 



4 



tf 



/ O MO Q 



E B 



O 



SLIDE VALVE SEAT 
(l23\ 




204 1902 MODEL BRAKE VALVE 

for the brake pipe air to pass to the atmosphere in a 
graduated service application, and should automatically 
close the opening when the brake pipe pressure has been 
reduced the desired amount to operate the triples with 
a graduated application. It should also have a large and 
direct opening to the atmosphere to exhaust the brake 
pipe air quickly in an emergency, so the triples will oper- 
ate quick-action. 

The New York Brake Valve is shown in a sectional 
view. The brake valve body, 101-A, contains a main slide 
valve, 114-A, which is moved back and forth over the 
slide valve seat by the slide lever 118 and links 116; this 
lever is attached to lever shaft 120, and moved by handle 
123. Plugs 96 can be taken out to oil the slide valve 114. 
Main reservoir air enters the body of the valve, passing 
up into chamber B, and is all around the sides and on top 
of slide valve 114-A. It also passes to the red hand of 
the gage and to the high pressure side of the duplex 
governor. The black hand gets air from the brake pipe 
side of the brake valve. When this valve is in full re- 
lease position, main reservoir air passes directly through 
the port a into chamber A, which is connected with the 
brake pipe directly, so that in this position main reservoir 
air can equalize with the brake pipe; if the duplex gage 
is right both hands will show the same pressure. When 
the handle 123 is moved back to 'running position, port a 
is covered by the end of the slide valve so no air can pass 
through a; main reservoir air must then pass from B 
under excess pressure valve 97, raise it against the stiffness 
of its spring 90, pass through E into the cavities M-M 
in the face of the slide valve and through a into A. Brake 
pipe pressure is also holding valve 97 down in addition 
to the stiffness of spring 90, so that with' main reservoir 
pressure on one side and brake pipe pressure on • the 
other side of 97, spring 90 is able to maintain a steady 
difference in these pressures, at whatever amount the 
main reservoir pressure may be. This difference is usually 
20 pounds. 



1902 MODEL BRAKE VALVE 



205 



Two sectional views are shown giving the position of 
the excess pressure valve 97, the ports from B to E, 
and showing the main reservoir, brake pipe and gage 
connections. The connection to the supplementary reser- 
voir and port H is shown on the side elevation.- 

In the lower part of the valve body, 101-A, is a piston, 
104- A, moving in a bushing; this piston by means of the 




GAGE 

RED HAND 

MAIN 
RESERVOIR 
PRESSURE 
JO 
MAIN 
RESERVOIR 



graduating valve lever 112, can move the graduating or 
cut-off valve 110, which rests against the lower face of 
slide valve 114-A, and in its normal position covers the 
port F that is connected by a passage through the middle 
of the slide valve with port G, which in service position is 
open to the atmosphere through cavity C. When the slide 
valve is moved to the first notch in service application 
position, brake pipe air can flow from A through a, ports 
F and G into C, and reduce the brake pipe pressure. 
Chamber D on the other side of the piston 104-A is con- 
nected with the supplementary reservoir 155, which has a 
pressure in it at the beginning of the brake pipe reduction 



206 OPERATION OF BRAKE VALVE 

equal to that in the brake pipe. As the brake pipe press- 
ure is reduced, the air in chamber D and 155 expands, 
and moves piston 104-A towards the reducing brake pipe 
pressure in A, this in turn moves cut-off valve 110 back 
and closes port F, thus cutting off the flow of brake pipe 
air to the atmosphere, without any movement of the 
handle 123 to lap position; this is expected to reduce the 
brake pipe pressure about 4 pounds. A further movement 
of handle 123 to the next service notch will move valve 
114- A so that port F will be again opened; when the 
proper reduction has been made, cut-off valve will again 
close port F. Successive reductions can be made by 
moving handle 123 to the next service notch till the last 
one is reached, when the brake pipe pressure will have 
been reduced about 23 pounds, and the brakes applied 
in full service. The size of the supplementary reservoir is 
such that when the air in it expands into the additional 
space made when piston 104-A moves clear forward, the 
pressure will be reduced from 70 to about 47 pounds, or a 
little over two-sevenths of the original pressure; with a 
higher pressure the total reduction will be greater. 

To reduce the brake pipe pressure suddenly and 
directly, 123 is moved at once to the emergency position; 
this opens the large ports J-J to A so that brake pipe air 
passes through two passages ; one on each side of F-G 
and out at K to C. This sudden discharge of brake pipe 
air through the large openings will reduce the pressure 
quickly and operate the triples quick-action. After any 
application, whether service or emergency, the brake valve 
should be placed in full release position till the brake pipe 
has been charged its full length, and all triples moved to 
release position, if it is desired to release all brakes 
properly. 

If piston 104-A has been moved forward by the press- 
ure in chamber D at the time of a reduction of brake pipe 
pressure, it must be moved back to its normal position 
when the brakes are released if it is to be ready to move 
cut-off valve 110 to graduate the next brake pipe reduc- 



OPERATION OF BRAKE VALVE 207 

tion. To do this some of the air in chamber D and reser- 
voir 155 must be discharged to the atmosphere. This is 
done through port and passage O, which passes through 
the valve cover 115-A as shown in illustrations, back 
into the valve body 101-A and out to C through port J 
when the valve is in full release, or through cavity P in 
the slide valve when in running or lap position. Another 
passage, H, connects chamber D at all times with reservoir 
155, so that when air can pass out of chamber D through 
O, it can also pass out of reservoir 155. With air exhaust- 
ing from chamber D and brake pipe pressure in A, piston 
104-A is at once moved back to its normal position; also 
moving cut-off valve 110. In the end of piston 104-A 
is a valve, 180, that closes port O when the piston is in 
the normal position and the brake valve in full release, 
running position or lap, and prevents any air from chamber 
D flowing out at port O. Air from the brake pipe can 
flow from A up past ball valve 184, and recharge chamber 
D at all times when the pressure is less in D than in A; 
but cannot flow back into A as the valve 184 prevents this. 
This recharges chamber D and reservoir 155 as soon as 
piston 104-A moves to normal position and seats valve 
180, closing passage O. The opening past ball valve 184 
and through the piston into chamber D, is much smaller 
than O, so chamber D air can be exhausted through O 
faster than it can feed in at 184, this ensures the move- 
ment of piston to its normal position. The older pattern 
of Vaughn-McKee valve does not have this recharging 
attachment, and in all cases in releasing brakes the valve 
must be replaced in full release an instant to discharge 
the air from chamber D, then moved to running position 
to recharge chamber D, in order to get the graduating 
action of piston 104. 

As the supplementary reservoir is supplied with air 
from the brake pipe, while this reservoir is charging after 
an application and release of the brake on a lone engine 
with the older type of the Vaughn-McKee valve, the brake 
pipe pressure will be reduced at the instant of placing the 



208 BRAKE VALVE DEFECTS 

valve on running position. This reduction of pressure may 
apply the engine brake; as soon as air begins to pass the 
excess valve the brake should release. 

If the supplementary reservoir pipe is broken or leak- 
ing so a blind joint must be made at the valve, there will 
be so little air in chamber D that the equalizing piston 
will not move valve 110 to graduate and stop the flow of 
air from brake pipe, and handle 123 must be moved to 
lap position to stop the discharge of brake pipe air. 

As this valve has two sets of exhaust ports, one small 
for the service application and a large port for the emer- 
gency application, the work of reducing the brake pipe 
pressure is very easily regulated. 



DEFECTS OF THE BRAKE VALVE 

If air leaks past main slide valve into brake pipe, it 
will not maintain excess pressure, if the valve is in 
service or lap position during an application of the brake 
this leak will recharge the brake pipe and release the 
brake. To test for this leak, place the valve on lap, close 
the cut-off cock and start the pump; any leak into the 
brake pipe will be shown on the black hand. If the leak 
is only shown when the valve is in running position, the 
excess pressure valve is at fault; it usually only needs 
cleaning. While doing this do not scratch either the valve 
or its seat, or it will surely leak after cleaning. If the 
cut-off valve 110 leaks, it will not stop the flow of air 
from the brake pipe in a service application; you can hear 
the continuous blow at the exhaust opening. This blow 
will stop if you move the valve back to lap. If the cut- 
out cock is closed, the black hand will drop to zero, unless 
there is a leak into the brake pipe cavity A. A leak 
through the leather gasket under the cap 115-A that 
allows main reservoir air to get into port O, will cause 
a blow at the exhaust in any position between lap and full 
release. In any other position it will charge chamber D 



BRAKE VALVE DEFECTS 209 

direct from the main reservoir. The openings in the 
gasket at O should be the exact size of the port O. 

A leak from the supplementary reservoir or its con- 
nections, if to the atmosphere, is easily detected, and 
should be remedied if the automatic closing of the cut- 
off valve 110 is to be satisfactory. This leak will reduce 
the pressure in the reservoir so the piston 104 will not 
move. A leak from chamber D back into the brake pipe 
can be detected by closing the cut-out cock under the 
brake valve, placing the valve in emergency for an instant 
to empty chamber A and then in the second service notch; 
a leak into chamber A will be shown on the black hand. 
This leak may be past the leather packing ring or by the 
ball valve. Before making this test be sure main slide 
valve does not leak from main reservoir into brake pipe. 
Lost motion between handle 123 and main slide valve will 
allow the slide valve to leave the ports only partially 
open; this will affect the release of the brake very 
seriously. This affects a brake pipe reduction when made 
in the first graduating notch. 



THE STRAIGHT AIR BRAKE 

The Straight Air Brake valve shown in Figs. 1 and 
2, has a slide valve 227, which is moved by the lever 222 
with its lever shaft 224, and slide valve lever 232. When 
in release position, Fig. 2, the port b, leading from the 
brake cylinder pipe is connected with the exhaust e by the 
cavity c of the slide valve. To apply the brake the handle 
222 is moved to application position. This moves valve 
227 so as to lap or cover the exhaust port e and uncover 
port b. Main reservoir air, which has been reduced to 45 
pounds at the reducing valve, Fig. 3, can then flow from 
A into b and thence to the double check valves and brake 
cylinders. Gasket 121 prevents leakage of air along the 
shaft 224. The reducing valve shown in Fig. 3 is located 
between the main reservoir and the brake valve. The 
diaphram complete consists of the stem 21, the washer 



210 



THE STRAIGHT AIR BRAKE 



23 and the rubber diaphram 32. It is held down against 
the air pressure in B by the regulating spring and its stem 
19. As long as the pressure in B is less than the regulat- 



r~\ 



THE NEW YORK AIR BRAKE CO 

Straight Air Engineer's Valve, , 

i /// 




TO MAIN RESERVOIR 
9/SPlPE. 

ing spring is adjusted for, which is 45 pounds, the feed 
valve 26 is held off its seat. When this pressure reaches 
45 pounds, the spring should allow the diaphram to raise 
and allow feed valve 26 to seat, thus shutting off the 
flow of air from A into B. 

The safety valve, Fig. 6, has a release lever to raise 
the valve off its seat to lower the brake cylinder pressure 



B-2 BRAKE VALVE 



211 



when necessary. This safety valve for the driver brakes 
can be located in the cab, if desired, and is to set at 52 
pounds, as is the tender brake safety valve. 

Safety Valve Fig. 6, 

With Release Lever. 




Fig. 3 
Reducing Valve, 



The double check valve used is shown in Fig. 4, 
question 38. The same rules apply to the operation of this 
straight air brake as to the Westinghouse equipments. 

The B2 Brake Valve is designed to operate the auto- 
matic brake on train and engine in the same manner the 
1902 model valve does, and in addition apply the driver 
brake with straight air, this does away with a separate 
straight air brake valve. It also operates an accelerator 
valve that passes air out of the brake pipe to the atmos- 
phere during a service application on a long train and 
thus makes the operation of the triple valves more pos- 
itive and quicker. There is a duplex controller that regu- 
lates the supply of main reservoir air to the brake valve 



B-2 BRAKE VALVE 



213 



by reducing it to brake pipe pressure before it reaches 
the brake valve, so the pressure in the main reservoir 
side of the valve will not rise above the standard desired 
in the brake pipe, this does away with the excess pressure 
attachment used with the 1902 model. The arrangement 
of this equipment is shown in piping diagram on this 
page. 

There is no ball check valve 184 in the piston, chamber 
D being charged from the air in B around the slide valve 




EVI9CT 
EV192 

QT29- 
QT3iz 
QJ30- 

B-2 Brake Valval 



JACCE^KATOO 




VM.VE «t$t*VO<* 



y./--°^ 



FACE OF SLIDE VALVE 



4 • fira §9 I • 

-I _^4.)g r.^ik 




W ***** CVUNOCR» 

through a small port W in the valve seat leading into 
passage H and the supplementary reservoir. Passage O 
and vent valve 180 in this valve serve the same purpose as 



214 OPERATION OF.B-2 BRAKE VALVE 

in the 1902 model, to discharge air from chamber D so 
that brake pipe pressure can return piston 193 to its normal 
position, when valve 180 closes port O. 

A sectional view of the B2 valve is shown, also a plan 
of the face of the slide valve and its seat. The chief 
differences between this valve and the 1902 model are the 
ports in the slide valve and the seat. Two ports, E and 
V, in the seat are connected by a cored passage shown by- 
dotted lines through the valve body and located above 
passage H, into this passage the pipe leading to the brake 
cylinders is attached. When the slide valve is clear ahead 
in full release it uncovers port E so air from the top of 
the valve in B can pass through the reducing valve set at 
40 pounds, to the brake cylinders, this applies the engine 
brake straight air. Air from B passes by the end of the 
slide valve and also through ports M in the slide valve 
into the brake pipe as fast as the air can pass the con- 
troller, releases the train brake and charges the brake 
pipe and auxiliaries. Port T in the seat, leading to the 
accelerator reservoir is open through J in the slide valve 
and exhaust C to the atmosphere and port O is the same 
as explained with the 1902 model. Port W is open and 
keeps chamber D equalized with B. In this position the 
train brake is released and the driver brake set straight 
air. 

In running position the slide valve is moved back 
covering port E so no more air passes to the brake cylin- 
der pipe, port V in the seat registers with R in the valve 
so brake cylinder air can exhaust through R, J and C, 
this releases the driver brake. Air can pass to the brake 
pipe through the large ports M in the slide valve so run- 
ning position releases both the train and driver brakes. 
Ports O and T are still open to J and the atmosphere. 
On lap all ports are blanked except port O, this is left 
open to return the piston and graduating valve to normal 
position, if a service reduction has been made so the 
valve will graduate at the next reduction. 

In the graduating positions, ports F and G are opened 



OPERATION OF B-2 BRAKE VALVE 215 

by a movement of the slide valve and port F closed by 
the graduating valve as with the 1902 model. But as port 
S in the valve is opened at the same time with port F, 
when air is flowing from F into G, it is also flowing 
through S, the passage X and into the opening Ac that is 
connected by port T in the seat and Y to the accelerator 
reservoir. As soon as the proper brake pipe reduction 
for that notch is made valve 110 will close ports S and F. 
A movement of the handle to the next notch will open 
ports S and F again and valve 110 will close them; 
brake pipe air flows to the accelerator valve chamber at 
the same time it flows through F and G and exhaust C. 
When the last graduating position is reached the restricted 
passage N in the end of the slide valve has been moved 
over port V so air begins to flow from the brake valve to 
the brake cylinder. As the engine triple valve has been 
sending air to the cylinders during the service application 
the supply of air through port V tends to maintain the 
pressure during a full application. The action of the 
valve in emergency is exactly like that of the 1902 valve 
before described. The reducing valve used with this 
equipment is the same one described in connection with 
the Straight Air Brake. 



B 3 BRAKE VALVE 

This valve in some respects is similar to the B2 just 
described. The engine and tender brake have triple 
valves for automatic service and double check valves to 
enable straight air to be used, which can be applied in 
full release or emergency positions releasing it in run- 
ning position whether applied with straight air or auto- 
matically, with this valve the main reservoir pressure is 
reduced to 40 pounds before reaching the brake valve for 
use in straight air applications. It operates the acceler- 
ator valve in the same manner as the B2, using the same 
design of divided reservoir. 

The piping diagram of the B3 when compared with 



OPERATION OF B-3 BRAKE VALVE 



217 



the B2 will show some of the differences. A sectional 
view of the complete valve, also a plan of the slide valve 
and its seat is shown so the differences between the ports 
and cavities in the B2 and B3 are plain. The valve cover 
is fastened to the body by tap bolts instead of screws; 
port o is cored through the body instead of being drilled 
through the cover, it does not show in the sectional side 
elevation. The plan of the valve seat and body shows a 
pipe bracket bolted to the side, dotted lines show the 
cored passages to port N and from port E through which 
air passes on its way to the brake cylinders in a straight 



til W B^ Brake Valve. 



, i" COPPER P« 
TO ACCCLERATOf? 
«C&ERVC'» 




SUPPLEMENTARY 



air 
the 



«tS£Rvoia — x^_^' V y cuwor» 

application. V is the straight air exhaust port; C is 
brake pipe exhaust port; o is the discharge port 



218 OPERATION OF B-3 BRAKE VALVE 

through which the air from behind piston 311 can pass 
out in full release, running and lap positions ; T is the 
port leading to the accelerator reservoir ; W leads to the 
supplementary reservoir and chamber D behind piston 
311; A is the opening through which main reservoir air 
that enters at B can pass into the brake pipe in release 
and running positions. On the plan of the face of the 
slide valve, M-M are two openings in the end of the 
valve through which this air passes in release and run- 
ning positions as well as passing by the end of the valve 
in full release; port F is connected to G by a passage 
through the body of the valve 312, better shown in the 
side elevation and used in service application to pass air 
from A to C; ports J-J are likewise connected with K 
and large enough to make the emergency reduction from 
A to C; groove P in the face of the valve serves to charge 
chamber D and supplementary reservoir through port W 
in release and running positions; ports L-L are connected 
by a cavity in valve 312, they register with ports N and 
E for the straight air application in full release; cavity 
R connects E and V in running position to release the 
straight air brake, and to discharge air from port o in 
release, running and lap position. Port S connects with 
cavity through Ac, a passage shown by dotted lines ; cavity 
Ac is oyer port T leading to the accelerator reservoir in 
the graduating positions so that some of the brake pipe 
air escaping during a service reduction can flow to the 
accelerator reservoir and build up a pressure there to 
operate the accelerator valve; port T is open to J in 
running position so air can all escape from the acceler- 
ator reservoir. 

Main reservoir air reduced to the standard brake pipe 
pressure at the duplex controller comes into the brake 
valve at B and is around the slide valve, in automatic-re- 
lease and straight-air-application position air flows through 
ports M and by the end of valve 312 into the brake pipe 
and equalize there with B. Main reservoir air also passes 
the single pressure controller set at 40 pounds into port 



OPERATION OF B-3 BRAKE VALVE 219 

N then through port E, the double check and into brake 
cylinder. Port o is open to cavity R and port V so air 
behind piston 311 is discharged to allow brake pipe air to 
force the piston to normal position, when in normal 
position valve 180 closes port o at that end and no more 
air can pass through o } the supplementary reservoir will 
then charge through port W; port T is open through J 
and C. Placing the brake valves midway between release 
and running position will lap the straight air ports N and 
E so no air can pass in or out of the brake cylinders 
through the brake valve and will hold the engine brakes 
partially applied. 

Running position will release both automatic and 
straight air brakes, the straight air will come back through 
port E and passing into cavity R will escape through V 
into C. In lap position all ports are closed, except o, 
this open port is to return piston 311 to normal position 
in case it has been moved in a service application and 
the brake valve moved to lap. There are five service or 
graduating positions, each having a notch in the quadrant, 
they are calculated to make automatic reductions from 70 
pounds brake pipe pressure of 5, 8, 11, 15 and 23 pounds, 
or in that proportion for any higher pressure. In any 
service reduction, ports F and S in the face of valve 312 
are open, F to the atmosphere through G ; S to Ac and 
the accelerator reservoir till the brake pipe reduction is 
sufficient to allow air in chamber D to move piston 311 
and cut-off valve 317 to close them. In the last graduating 
notch cavity R opens to port N a very little so main 
reservoir air can flow from N to E, into the double check 
and cylinders and reinforce the automatic application if 
it has leaked below 40 pounds. 

In the emergency position ports J and K allow the 
brake pipe air to flash out to the atmosphere, this sudden 
reduction of brake pipe pressure operates all triples as 
quickly as possible. The straight air is also set full on 
through ports N and E in case the triple valves does not 
make the cylinder pressure on the engine above 40 pounds. 



220 



DUPLEX CONTROLLER 



The reducing valve for the straight air brake is a 
54-inch single controller, the regulating top is connected 
with a small pipe with the pipe leading from the B3 
valve to the double check, so the controller operates to 
close off when the pressure builds up in this pipe to 40 
pounds. With no air in this pipe the controller is open 
and main reservoir air comes as far as port N without 
any reduction. In all other respects the equipment of 
divided reservoir, accelerator valve, safety valve and high 
speed controller is the same as with B2. 




DUPLEX CONTROLLER. 



THE DUPLEX CONTROLLER 

This valve is located between the main reservoir and 
the brake valve ; its duty is to reduce the main reservoir 
pressure to that required in the brake pipe before reach- 
ing the brake valve. There are two forms of it in service, 
only the latest form of it is here illustrated. In its con- 
struction it is like the duplex pump governor, except that 
its valve has a leather seat. The regulating tops can 
be located in the cab and connected to the controller body 
by a copper pipe. One of the tops is adjusted for the 
ordinary brake pipe pressure, the other for the higher 
pressure used with the High Speed Brake. When one 
side is cut in by the union three-way cock the other is 
cut out, either one of the tw T o pressures can be carried in 
the brake valve and brake pipe. The description of the 
duplex pump governor and its operation will be sufficient 
to show how the controller operates. Air enters at the 
opening marked MR, if the controller valve is open it 
can pass through and out to the brake valve at BV. 
When necessary in steep grade work to have full main 
reservoir pressure in the brake valve the controller valve 
can be held open by screwing. the hand wheel up the full 
travel of its screw. 



THE ACCELERATOR VALVE 

This valve is intended to discharge brake pipe air 
during a service reduction in addition to that taken out 
by the brake valve. It has a divided reservoir; one side 
for the accelerator valve to which the valve is bolted, the 
other is the supplementary reservoir for the brake valve. 
When air from the brake valve during a service reduction 
passes through ports S and T to the reservoir it also 
comes through port Q over piston 65. With a short train, 
less than ten cars, port S is closed by the graduating 
valve before sufficient air has passed into the accelerator 
chamber to operate its valve. With a train of over ten 



222 



OPERATION OF ACCELERATOR VALVE 



cars the pressure in* the chamber will build up till it is 
sufficient to force piston 65 and with it stem 67 and valve 
74 down against the tension of spring 31 in the bottom 
of the valve. In valve 74 is an oblong port a and in the 
seat a A shaped port b. When valve 74 is moved down 
port a first opens to the pointed end of port b, and brake 
pipe air coming in at the opening TP begins to flow out of 
b slowly. As the valve 74 is moved farther down by the 
increasing pressure of the air above piston 65, ports a and 
b are opened wider till their full opening is made; this 
gives a gradual discharge of brake pipe air that with a 
long train begins about four seconds after the brake valve 
begins discharging air. It requires 15 to 17 pounds press- 
ure in the chamber to operate the valve. Through piston 
65 is a small port S through which air that comes over 
the piston can discharge into the space under the piston 
and then to the atmosphere through port T ; air flows out 
here at the same time it comes into the reservoir and 
prevents any sudden rise of pressure in the reservoir. 




When piston 65 moves down it uncovers port R in the 
bushing, this also takes air out of the reservoir. As soon 
as the graduating valve laps port S in the brake valve, 



THE HIGH SPEED CONTROLLER 



223 



no more brake pipe air will flow to the chamber; ports 
S and R in the accelerator piston will then gradually re- 
duce the pressure in the chamber and allow spring 31 to 
move valve 74 and piston 65 up, gradually closing ports 
a and b. When piston 65 closes port R the flow of air 
out of S alone is so much slower that piston 65 gives a 
very slow closure to port b. The gasket 70 makes a tight 
joint on its seat around stem 67 when the valve is closed, 
so brake pipe air cannot escape around the stem. 



THE HIGH SPEED CONTROLLER 

The high speed controller connects with the brake 
cylinder pipe at BC and to the brake pipe at BP, so that 
brake pipe air pressure is always in the body of the valve 
and when greater than brake cylinder pressure will hold 




\HSr05 
\HSIIO 
To Brake Cylinder* H S 109 

*-Pipe 



piston 107 in normal position as shown, leather gaskets 
are on each side of the piston to make the joint tight. A 
moderately large opening around the valve 108 allows air 
from the cylinder to reach the safety valve freely and 



224 THE AUTOMATIC CONTROL 

rapidly reduce any excess of pressure above that the 
safety valve is set for, this takes place in a service applica- 
tion. In an emergency application the brake pipe pressure 
is suddenly reduced below what the brake cylinder can 
build up to, and piston 107 will move over to the right 
with the leather gasket resting against the seat C. This 
brings the small valve 108 under passage G so the cylinder 
air blows down gradually in this position till the limit 
for which the safety valve is adjusted is reached, this 
should be 53 pounds. Ports D and F are to allow cylinder 
air quick access to the *ends of the valve 108 and piston 
107 so they will move with a low difference of pressures 
on piston 107. 

The Automatic Control equipment of the New York 
Brake Co. is for locomotive service, either with or with- 
out the train brakes. The piping diagram shows the 
various parts, the automatic brake valve; double pressure 
feed valve ; reducing valve ; pump governor ; strainer 
check valve and safety valve are the same in construction 
and operation as those described in answer to questions 
35-37, so they need not be described again here. The 
straight air brake valve and double throw check valve 
have been described in the New York equipment a few 
pages previous. The straight air brake valve is used to 
pass air directly to and from the locomotive brake cylin- 
ders, it does not send any air to the Automatic Control 
valve as the independent brake valve does to the distrib- 
uting valve in the ET equipment. The double throw 
check valve is located in the pipe line between the brake 
cylinders and the straight air brake valve on one side and 
the Automatic Control valve on the other side; the duty 
of this double throw check is to close the exhaust to the 
straight air valve when the control valve is operated and 
vice versa. A safety valve is attached to the control 
valve and a release valve or bleeder to the retaining 
pipe between the control valve and the automatic brake 
valve. Stop cocks are located in the various pipes to cut 
out the air when necessary and choke fittings near the 



226 



AUTOMATIC CONTROL VALVE 



hose connections leading to the tender brake and engine 
truck brake to hold the air back in case either of these 
hose burst or come uncoupled. The double chambered 
reservoir is the same as shown with the ET equipment. 



Automatic Control Valve 



fDP52C^ 



PTI56 
CVI07- 




The Automatic Control valve is shown in two sectional 
views, the view at the right shows the passages to the 
double chambered reservoir, the left one a sectional view 
from in front. On another page is shown a diagrammatic 
view, as the air ports and valves cannot be shown in a 
correct sectional view. This cut shows the double 
chambered reservoir attached at the bottom of the valve, 
the reservoirs are of such a relative size that they will 
equalize at 50 from 70 pounds in the auxiliary. 

The valve is in full release position, triple valve piston 
3 is at the bottom of its cylinder so feed port at G is 
open, slide valve 4 and graduating valve 10 are in normal 
position to exhaust air from the control reservoir and 
chamber D above control piston 2. Control piston 2 is 
at the upper end of its cylinder in normal or release 
position, by it exhaust valve 7 is held open so brake 
cylinder air coming in at C can escape at exhaust N. 
Main reservoir air comes in at A at full pressure around 
admission valve 1, spring 8 holds this valve on its seat 
when there is no air pressure to do it. Brake pipe air 



FULL RELEASE 




TO LEVER RELEASE 




o 2 



TO BRAKE VALVE 

Automatic Control Valve. 



228 OPERATION OF AUTOMATIC CONTROL VALVE 

comes in over piston 3 at BP; at IV is the exhaust 
through the control cylinder release pipe connected to the 
automatic brake valve; the control reservoir pipe is at II 
and the continuous feed pipe from the reducing valve 
pipe of the straight air valve to the auxiliary reservoir 
is at VI. The safety valve is attached to port L and will 
blow down the pressure in the control reservoir to 
standard with either a full service or emergency applica- 
tion ; with the triple valve on lap the safety valve is cut 
out. 

To operate this valve after the auxiliary reservoir is 
charged to standard pressure from the brake pipe, a brake 
pipe reduction is made. Piston 3 at once moves up follow- 
ing the reduction in F carrying with it graduating valve 
10 and slide valve 4; closing feed groove G; moving valve 
10 to uncover port J in slide valve 4, which is moved 
up so port J registers with E in the seat, also lapping 
exhaust port M. Air from the auxiliary reservoir now 
flows into the control reservoir and D over control piston 
2 building up a pressure in both places. When the press- 
ure in the auxiliary is a little less than that of the brake 
pipe, piston 3 will move down carrying valve 10 with it 
and lap port J so no more air can go into D and the 
control reservoir. Pressure on piston 2 will move it 
down carrying valve 7 down over exhaust port N, a 
farther movement will push preliminary admission valve 
Al off its seat in admission valve 1, this allows air in O 
to flow out into B ; as air cannot get by the guide case 
or extension of 1 as fast as it gets out, this tends to 
balance valve 1 so piston 2 can open it easily. Main 
reservoir air then flows into B and the brake cylinders 
till the pressures there are a little above that in D and 
the control reservoir, piston 2 then moves up and allows 
valves 1 and Al to close, but does not open exhaust 
valve 7, this holds the engine brakes applied automatically. 
If, on account of leaks, the brake cylinder pressure drops, 
it will be less than in D, piston 2 will at once open the 
admission valve and raise the cylinder pressure and in 



OPERATION OF AUTOMATIC CONTROL VALVE 229 

B till it can push piston 2 up so admission valve can 
just supply the leak. For a full application the brake 
pipe pressure is reduced 20 pounds from 70, this will 
hold triple piston up and slide valve ports open, equalizing 
the auxiliary and control reservoirs. 

If, on a full application the pressure in the control 
reservoir exceeds the adjustment of the safety valve, it 
will blow down, the brake cylinder pressure will not build 
up any higher than that in D. Air from the control 
reservoir can flow to the safety valve from port E 
through U, cavity V in valve 10 and port W into L. 

When an emergency application is made, piston 3 and 
its valves make a full travel at once, valve 4 uncovers port 
E so auxiliary air can flow quickly into D forcing control 
piston 2 down, operating its valves in short order. Port 
P in the slide valve now registers with port L so air 
from the auxiliary and control reservoirs can get to the 
safety valve. A small port in the automatic brake valve 
(if the rotary is in emergency position), will send a 
supply of main reservoir air through the pipe marked CR 
on the piping diagram into the control reservoir at II, 
this will hold the pressure there up to where port P can 
handle it all to the safety valve, thus giving a higher 
braking pressure in the emergency than in a service ap- 
plication. 

A quick-action cylinder cap for the triple valve can 
be furnished if desired that will vent some of the brake 
pipe air to chamber B below control piston, this will 
operate the car triples quicker than when the reduction 
is made at the brake valve only. 

To automatically maintain the pressure in the auxiliary 
reservoir there is a pipe connected at VI that leads from 
the reduced pressure pipe between the reducing valve and 
the straight air brake valve, on the diagram this is 
marked PC. If from any cause the pressure in the 
auxiliary drops below the adjustment of the reducing 
valve (which should be set at 45 pounds), air can flow 
into the auxiliary and set the brake through the control 



230 



STRAINER CHECK VALVE 



valve up to that pressure. To do this it moves the triple 
piston up against the depleted brake pipe pressure and 
passes into D, thus operating piston 2. There is a 
strainer check valve in pipe PC to prevent air at over 
45 pounds getting back into the reduced pressure pipe 
and a stop cock to cut out the air in case the reducing 
valve gets out of order or the brake pipe is cut out. If 
at any time the pressure in the reduced pressure pipe 

Strainer and Check Valve. 

^DC 93 /DC 92 

/DC 94 //DC 72 DC I 
' /DC 95// DCM9 /DCl 




DC 120 



exceeds that in the brake pipe the engine brake will set 
and stay set. 

To operate the locomotive brake automatically leave 
the straight air brake on release position and make the 
proper brake pipe reduction with the automatic brake 
valve. When releasing avoid overcharging the engine 
auxiliary by leaving the brake valve on full release too 
long as when you go to running position the drop in 
brake pipe pressure may set the engine brake. If the 
engine brake is to be held set and the train brake released 
go to full release and stay there a few seconds till all 
triples release, then go to holding position, this will 
not overcharge the brake pipe and will hold the locomotive 
brakes set, because air from control reservoir cannot 
escape after its triple goes to release till the brake valve 
is put in running position. When the straight air brake 
is used leave the automatic brake valve on running posi- 
tion and apply and release the engine brake with the 
straight air valve. To release the engine brake after it 
is set automatically without releasing the train brake also, 



QUICK ACTION TRIPLE VALVE 231 

use the hand release valve or bleeder that is connected to 
control reservoir by pipe CR ; by bleeding this reservoir 
piston 2 will be moved to open exhaust valve 7. The 
straight air brake valve will not release the engine brake 
when set automatically, the double throw check valve 
will prevent it. 

At any time when set automatically the engine brake 
can be released by holding the bleeder open, but it has 
no effect when set by straight air as the double check 
valve will close the opening from the cylinders to the 
control valve. 



THE QUICK ACTION TRIPLE VALVE 

The Quick Action Triple Valve is used on passenger 
and freight cars and some passenger tenders. The one 
shown in section is the older type of freight car triple. 
The passenger triple valve for 12, 14 and 16-inch brake 
cylinders has the graduating valve 48 located on top of 
slide valve 38, and the service port through valve 38 as 
well as in its seat, the vent valve piston has the port 
F through the stem 129. The new type of freight triple 
also has the vent valve piston made like the passenger 
triple. These triples are shown in Plate R-24. 

As some of the moving parts are at right angles to 
each other, this cut does not show them as clearly as the 
diagrammatic views. The same reference numbers and 
letters are used in both illustrations. Referring to page 
196, the triple valve body 125 contains the two bushings 
in which main piston 128 and the valves 38 and 48 move; 
126 is the front cap which contains vent valve 71 and its 
spring 132; it also holds the stem of 129 in position. The 
vent valve seat or "middle section" 130 makes the cap 
for the cylinder of the triple piston 128. 127 is the side 
cap and covers the quick-action valve piston 137. Main 
piston 128 is extended so that it forms a cylinder in 
which another piston, 129, is fitted, the stem of which 
passes through 130 and is held from moving to the right 



OPERATION OF QUICK ACTION TRIPLE 233 

by a clip or piston stop 142, so that when piston 128 
moves to release position vent valve piston is in its normal 
position, and a chamber, G, is left between the two 
pistons. A small port F through piston 129 allows brake 
pipe air to pass in and out of chamber G. This port is 
of such a size that when piston 128 moves slowly to the 
left in a service application, the air in G can pass out 
to the brake pipe side of piston 129, and piston 129 will 
remain stationary with regard to 130 and vent valve 71, 
as shown in service position. This vent valve is held on 
its seat by the pressure of the brake pipe air and 
spring 132. 

In a graduated service application when the brake pipe 
pressure is reduced in A the auxiliary pressure in the 
auxiliary side moves piston 128 towards the decreasing 
brake pipe pressure, first closing the feed port B and 
moving graduating valve 48 with the piston. As soon as 
the lost motion between the piston shoulders and exhaust 
valve 38 is taken up valve 38 moves and closes the exhaust 
port so no brake cylinder air can escape to the atmosphere. 
The port to the brake cylinder under valve 48 is next 
opened, and air from the auxiliary flows to the cylinder, 
applying the brake. When the flow of brake pipe air out 
of the brake valve stops, the reduction in A also stops, 
and as valve 48 is still open the auxiliary pressure soon 
gets lower than that of the brake pipe so piston 128 is 
moved to the right and closes valve 48, but does not move 
valve 38 ; this holds the brake set. Another brake pipe 
reduction produces the same movements of the piston and 
valves and so on till the brake pipe reductions make the 
pressure lower than that of the auxiliary, when the 
piston will not move back to close the graduating valve 
48. To release the brake the brake pipe pressure is raised 
higher than the auxiliary, this moves piston 128 and valves 
38 and 48 to release position, covering the service port 
and opening the exhaust port. 

The triple piston 128 makes a full stroke in either 
service or emergency application, the edge of cylinder 128 






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EMERGENCY APPLICATION 235 

striking the leather gasket 133, so that no graduating 
spring is used to assist in stopping the triple piston in the 
service position, and the piston does not get any assistance 
from a graduating spring when starting from emergency 
or full stroke towards release position. 

If the reduction in brake pipe pressure is made so 
suddenly that the air in chamber G can not pass through 
port F fast enough to equalize with the brake pipe reduc- 
tion, the pressure of air in G will move piston 129 over at 
the same time piston 128 moves. The stem of 129 will 
push vent valve 71 away from its seat, as shown in the 
emergency application; brake pipe air from the chamber 
around valve 71 can flow rapidly into passage H, and 
thence against the quick-action piston 137. This in its 
turn is moved to the right by the pressure of brake pipe 
air and quick-action valve 138 is unseated, opening a large 
passage for auxiliary air to flow through K into L — L, 
forcing check valve 117 off its seat ; the air also passes into 
the brake cylinder through the usual opening at the grad- 
uating valve. No air from the brake pipe reaches the 
brake cylinder, only that from the auxiliary, but the 
auxiliary air passes through such large ports K and L 
that the equalization between the auxiliary and cylinder 
is almost instantaneous after valve 138 is opened. As 
soon as these pressures have equalized, check valve 117 
closes and prevents brake cylinder air flowing back into 
L and thence around the stem of piston 137 to the atmos- 
phere. In the meantime air in chamber G has equalized 
through port F so that spring 132 can push vent valve 71 
and piston 129 to their normal positions. When vent valve 
71 seats, no more air flows from brake pipe to passage 
H ; air escaping from ports M and J at once reduces the 
pressure on piston 137, which is moved to the left, its 
normal position, by the stiffness of spring 140. Valve 
138 is closed and no more air can pass from the auxiliary 
into L, and all the quick-action parts of the triple valve 
are returned to their normal positions. Piston 128 having 
made a full stroke, valve 48 is open so that auxiliary air 



236 EMERGENCY APPLICATION 

can pass into the brake cylinder and keep the pressures 
equalized. With 70 pounds auxiliary pressure and the 
standard piston travel the equalization is the same for 
full service and emergency applications, 50 pounds per inch. 

Venting the brake pipe air to the atmosphere past valve 
71 and through ports M and J, should reduce its pressure 
below that in the auxiliary; this will hold piston 128 in 
service position. 

The sudden venting of brake pipe air to the atmosphere 
at this triple makes a sudden reduction at the next triple, 
which in turn operates quick-action, and so on from one 
triple to another to the end of the train; this is called the 
"serial" action. 

If there are, close to the head end of the train, several 
triple valves cut out, or defective triples that do not oper- 
ate the vent valve so as to vent enough air from the brake 
pipe, or cars with brake pipe only, the sudden reduction 
may not extend far enough to affect a quick-action triple 
so it works quick-action and continues the sudden serial 
reduction. About three "cut-out" triples next the engine 
is the limit to have the quick-action "jump over." At the 
rear end of the train the quick-action will jump more 
than three cars, because the volume of brake pipe air 
behind these defective triples is less than when they are 
near to the head end of the train. 

This type of triple valve does not send any brake pipe 
air to the brake cylinder; the brake cylinder pressure is 
the same with either a full service or an emergency appli- 
cation; so that the same increase of brake pipe pressure is 
required to move the triple valve to release position. 
When brake pipe pressure is restored so that it is greater 
than auxiliary pressure, or the auxiliary pressure has 
leaked down, or been bled out, brake pipe air passing 
through port F into chamber G moves piston 128 and 
valves 38 and 48 to release position; this closes the service 
port, opens the exhaust port to release the air from the 
brake cylinder, and opens feed port B to recharge the 
auxiliary. 



IMPROVED QUICK ACTION TRIPLE VALVE. 
for 12 and 14 Inch Passenger Cylinders. 

PLATE R 24. 




238 TRIPLE VALVE OPERATIONS 

If the piston 128 is in lap position, the volume of air 
in chamber G is so small that in an emergency reduction 
of brake pipe air, the pressures can equalize through port 
F and piston 129 will rarely move. If piston 128 is in 
service position, it is at the end of its travel and can not 
move any further. Therefore, after pistons 128 in the 
triples have responded to a service reduction, no matter 
how light, the quick-action parts of these triples will not 
move and a sudden serial action of these triples will not 
take place ; only a heavy service application. If the 
general rule to allow the air to pass out of the brake pipe 
at the brake valve or conductor's valve in cases of emer- 
gency or danger is promptly obeyed, all brakes that oper- 
ate will be applied with the greatest power and in the 
shortest time possible under the conditions. 

The passenger car triple shown in Plate R 24 has the 
graduating valve 48 on top of the exhaust valve 38 instead 
of at the end as shown in the next cut of R-6. Valve 48 
is fitted into a notch in the piston rod so that it moves 
with the piston 128, having its seat on top of valve 38. 
When the triple piston makes its first movement in a 
graduated application, valve 48 uncovers the air port 
through valve 38 and allows auxiliary air to pass into 
this port, although air cannot pass into the brake cylinder 
till the exhaust valve has moved far enough to open the 
ports into the cylinder. Then when the triple piston 
moves back to lap position, valve 48 moves across the top 
of 38 and covers the air port; the lost motion between 
the ends of valve 38 and the shoulders on the piston rod 
allows the piston and valve 48 to move without moving 
38. In this triple R-24, the passages from the auxiliary 
to the brake cylinder through the quick-action ports of the 
triple are much larger than in the older form, so that 
auxiliary and brake cylinder pressures equalize much 
quicker. 

The improved freight triple valve, R-6, is shown in 
emergency positions, vent-valve piston is moved down so 
that the opening of port F through the stem is inside the 



TRIPLE VALVE DEFECTS 239 

bushing of the center piece 130. This covering of port F 
chokes and retards the flow of air out of chamber G so 
that the vent-valve piston can not return to its normal 
position so quickly. It thus holds vent-valve 71 away 
from its seat longer, which makes a heavier reduction in 
brake pipe pressure. In all the later triples check valve 
117 and quick-action valve 138 have rubber seats, and port 
F is in the stem of piston 129. 

This later style of port F operates the same as the port 
through the piston, in each style the air from G can pass 
to the brake pipe the full size of port F. 



DEFECTS OF QUICK ACTION TRIPLE 

If vent valve 71 leaks, or is held off its seat, there will 
be a blow at the round port M, and sometimes at the two 
square ports J ; also, the brake may not release as brake 
pipe pressure can not be raised enough to move triple to 
release position. If the vent valve piston stem 129 is bent 
or the piston sticks in the cylinder of 128, valve 71 will 
be held open. This piston stem 129 and the cylinder of 
128 are easily damaged by improper handling, and should 
be carefully handled when taken apart. A small leak at 
valve 71 will show at the round hole M. If there is a 
blow at the square ports J in the triple shown in Plate 
Q-6, and not at M, or at N in the triples shown in R-6, 
air is probably coming from the quick-action valve 138 
and thence past the stem of 137, which is not an air tight 
fit in the cast iron body of the triple. If the air passing 
by valve 138. can not go by stem 137, it will, when the 
triple is in release position, pass check 117 and out the 
exhaust port or pressure retainer, or leakage groove. A 
leaky packing ring in piston 128 will affect the prompt 
movement of this piston to release position, as the air 
can leak by this defective ring and equalize the auxiliary 
with the brake pipe without moving the triple piston. A 
leak by this ring will not affect the quick-action operation 
of piston 129. If either of these rings are fitted too tight, 



"240 TRIPLE VALVE DEFECTS 

this particular triple piston may not move when the others 
do in the initial reduction of a service application, and 
when it does move it may cause quick-action at this 
triple only. If the packing ring in piston 129 leaks, the 
air in G can pass out by this ring and this triple is not 
likely to go into quick-action. 

A leak under the seat of valve 38 will allow auxiliary 
air to blow out the exhaust steadily. If under valve 48 in 
the triple shown in Plate Q-6, it will blow at the exhaust 
when the triple is in release position. With the triple 
shown in R-24 it will leak in lap position only, and 
then into the brake cylinder. If the packing ring in either 
piston 128 or 129 is too tightly fitted or gritty, the triple- 
may work slower than the others, and get quick-action 
with a moderate service reduction; this will vent a little 
brake pipe air to the atmosphere at that triple, but will 
not cause any other New York triples to work quick- 
action. If the stem 129 is bent or cylinder of 128 is bent 
or damaged, it may produce the same effect. This defec- 
tive triple can usually be located by the flash of air from 
ports M and J towards the ground which will blow the 
sand or dust. This brake may release at once if the 
pressure in the brake pipe is not reduced at that time 
below that at which that auxiliary and brake cylinder 
equalizes. 

Sand works into the ports M, N and J and may cause 
the quick action piston 137 to stick after a quick-action 
application ; this will hold valve 138 open so auxiliary air 
will leak away. 

Leaks by the gasket between the triple and the aux- 
iliary on a freight brake, or the triple and the cylinder 
head on a passenger brake allowing auxiliary air to pass 
to the cylinder, will give a steady blow at the exhaust 
port while the triple is in release position. 

If the port F has been enlarged or the packing ring in 
piston 129 is a poor fit, so it leaks, this triple may not go 
into quick-action when the sudden brake pipe reduction 
is made. 



COMPENSATING VALVE 



241 



The Compensating Valve is used in high speed service 
and is designed to reduce gradually the high brake cylin- 
der pressure in an emergency application with 110 pounds 
in the brake pipe and auxiliary to 60 pounds, when the 
valve will close and allow no more air to escape through 
it from the cylinder. 




THE COMPENSATING VALVE 



It consists of a piston, 100, that moves in a cylinder or 
bushing with several small ports in its side, in normal 
position the piston covers them so no air can pass out the 



242 OPERATION OF COMPENSATING VALVE 

ports. Below this piston is a diaphram and plate fastened 
to the piston that prevents the passage of air either way. 
The piston is held up in normal position by a stiff spring 
11, the tension of the spring is adjusted by the nut 12, a 
cap nut 13 makes an air tight joint at the bottom of the 
spring box, screwed into the side of the spring box is a 
check valve 85, containing a valve 86 with a small port a 
drilled through it. 

The brake cylinder is connected above the piston at A; 
a connection is made to the check valve case 85 from the 
passage H in the side of the New York quick-action triple 
valve. At any application of the brake air from the cylin- 
der comes into A and gives its pressure to the piston, if 
this pressure is any greater than the resistance of spring 
11 piston 100 will move down and uncover the air ports in 
the side of the bushing; this allows cylinder air to escape 
and reduce its pressure till spring 11 has power to force 
piston 100 up and close the ports. A thin leather gasket 
on top of piston makes a tight joint against a shoulder of 
the bushing so no air can leak out till the piston moves 
down. 

When an emergency action of the brake is made, brake 
pipe air from the quick-action triple comes through a pipe 
into the check case 85, forces valve 86 off its seat and 
equalizes in chamber B in the spring box. Spring 87 seats 
valve 86 so the air in B is confined there, but can grad- 
ually flow out through the small port a in the check valve. 
Its pressure comes against the diaphram under the piston 
and is added to the strength of spring 11, holding piston 
100 up against a stronger pressure of the cylinder air than 
the spring alone could. This prevents the cylinder air 
from blowing out at this valve till the air in B has had 
time to escape and it then blows down slowly. In this 
manner it compensates for the change in braking power 
as the speed of the train reduces. This matter of a change 
in braking power with a change of speed has been dis- 
cussed in the chapter on the High Speed Brake. 

The port where the cylinder air enters the valve at A 



TYPE J TRIPLE VALVE 243 

is restricted so the air can not flash into A at a high 
pressure, which aids in graduating the flow of air from 
the cylinder during an emergency application when the 
110 pound auxiliary pressure is used. 

These openings are of different sizes for different sized 
brake cylinders to make the small ones blow down at the 
same rate of time with the large ones. 



TYPE d TRIPLE VALVE 




Full Release. 



244 OPERATION OF TYPE J TRIPLE 

The type J triple here shown in two sectional views 
and a diagrammatic view is for high duty passenger 
service, it is both quick-action and quick-service and by 
the use of a supplementary reservoir of about twice the 
volume of the regular auxiliary reservoir ; the quick re- 
charge after a service application, a graduated release of 
the brake cylinder air and a high pressure at the emer- 
gency application are secured. 

Referring to the diagrammatic view of the release and 
charging position, air from the brake pipe passes in the 
regular way around piston 10, through feed groove D 
into E and the auxiliary, brake pipe air also passes bv 
check valve 1 (this valve is 139 in the sectional cut), 
into chamber F, then through port G into E, so the aux- 
iliaries are charged from two sources. Port G is of the 
proper size for the reservoirs it is to charge, port D is 
small, it is for equalizing the pressures during slight 
fluctuations in brake pipe pressure. Port H through 
graduating valve 2 registers with port I through slide 
valve 3 and port J in the seat so the supplementary is 
charging at the same time with the service auxiliary. x\ir 
from the brake cylinder can pass out through ports Q, 
T, cavity W, ports X and Y. The safety valve is con- 
nected to the brake cylinder at port Q and is set at 60 
pounds ; the blow-down attachment that operates in an 
emergency application only is shown in the lower part of 
the safety valve. 

In a quick-service application, piston 10 closes feed 
groove D, graduating valve 2 is moved back so cavity W 
no longer connects ports T and X, this closes the exhaust, 
port I is covered so no more air can pass to and from 
the supplementary, port R registers with S in valve 3, 
valve 3 next moves so ports G and K register as well as 
partly opening S to Q. Auxiliary air flows through R, 
S and Q to the cylinder ; brake pipe air flows from 
chamber F in a small volume through G, K, L, M and N 
in between pistons 5 and 8; these pistons are not air 
tight so the air passes into Q without moving them, this 



OPERATION OF TYPE J TRIPLE VALVE 245 

flow of air from the brake pipe makes a light local reduc- 
tion that affects the next triple so it moves to service 
position quicker than with the brake valve reduction 
alone. When the reduction at the brake valve stops and 
piston 10 moves back to lap it moves valve 2 only and 
laps port S from the auxiliary and port K so no more air 
passes to the brake cylinder. In a full service with a 
short train valve - 3 is moved far enough to lap ports G 
and K so no air comes from the brake pipe ; ports S and 
Q are opened wide, thus a larger amount of air can pass 
from the auxiliary to the cylinder at each triple with a 
short train than with a long one. 

In a restricted release, the brake pipe is recharged a 
few pounds above the auxiliary and the brake valve then 
lapped. Piston 10 will move both slide and graduating 
valves to release position, opening exhaust ports from Q 
around to Y; the recharging port G allows air to flow 
from the brake pipe; and ports J, H and I allow air to 
flow from the supplementary. This air from the sup- 
plementary will raise the pressure in E above that in C 
so piston 10 will move back closing port D, the graduating 
valve 2 will lap ports H and I so air can no longer flow 
from the supplementary and pressure in E will not rise 
higher, exhaust ports T and X are lapped by cavity 
W moving away from T. As main slide valve 3 will not 
be moved in this operation ports T and X will still register 
with Q and Y and air from the cylinder can pass out 
very slowly through the small port Z, connecting T and X, 
this allows air to exhaust from the cylinder slowly as 
long as valve 3 remains in this position. In the emer- 
gency application, piston 10 and valves 2 and 3 make a 
full travel at once, port Y is* open to Q so that auxiliary 
air flashes into the cylinder through a large port, port N 
is uncovered by this movement of valve 3 so auxiliary air 
passes between pistons 5 and 8. Piston 5 moves to the 
left and opens emergency valve 7, brake pipe flashes into 
Q and the cylinder ; piston 8 opens valve 9 so air from 
the supplementary in U can equalize through passage Q 



246 



THE K-4 TRIPLE VALVE 



with the cylinder and service auxiliary giving a much 
higher braking power than in the service application. 

The Blow-down valve shown in the bottom of the 
safety valve case has moderate sized ports Bl around it 
so in a service application the air from the cylinder can 
pass around 12 without moving it. In an emergency 
application the air comes from Q so fast that it raises 
valve 12, makes a tight joint at its top edge, this prevents 
cylinder air getting to the safety valve during an emer- 
gency application. In operating the J triple to make a 
gradual release charge the brake pipe sufficient to move 
piston 10 and its valves to release position, then lap the 
brake valve, the brake will release slowly through port Z. 
To have it release faster, recharge the brake pipe again 
to move piston 10 and valve 2 then lap brake valve again, 
this will open exhaust port wide for a short time, you 
can thus release the brake by successive steps down to 
zero. See explanation of question 55. 



QT346 
QT230. 




The K-4 Triple Valve of the New York Brake Co., 
in addition to the quick-action and quick-service features 
already explained in J Triple, has a piston stop 345 and 
its spring 369; an exhaust piston 339 that during a re- 
tarded release is moved to the left and chokes the exhaust 
port with its stem and thus restricts the exhaust. At a 



OPERATION OF K-4 TRIPLE VALVE 247 

release, if brake pipe pressure is raised much higher than 
the auxiliary, it forces triple piston 334 its full travel 
against the tension of piston stop spring 369, a port in 
slide valve then allows auxiliary air in at the right of 
exhaust piston 339 and force it to the left, its stem then 
chokes the exhaust opening so air passes out slowly. In 
this position piston 334 makes a tight joint against the 
bushing, no air will pass it and the auxiliary charges 
through the port from the brake pipe. When the aux- 
iliary and brake pipe pressures are nearly equalized, 
spring 369 will move stop 345, triple piston 334 and its 
valves 335 and 336 back to free release position, this 
allows air to pass around piston 334 through feed groove, 
also opens the space at the right of exhaust piston 339 to 
the exhaust, so this piston is moved back by its spring 
347, the exhaust port is then full sized. A leather gasket, 
358, on the exhaust piston prevents a leak of auxiliary air 
past the piston while it is held in retarded release posi- 
tion. See explanation of question 54. 



NEW YORK AIR SIGNAL VALVE 

The Air Signal Valve shown in section on this page 
has two chambers, A and B, in the upper and lower parts 
of the valve, separated by a rubber diaphram 12. Air 
from the main reservoir reduced in pressure at the reduc- 
ing valve to 40 pounds enters the signal valve from the 
signal pipe and passes into chamber A through the small 
opening d which serves to restrict the flow of air into 
and out of chamber A. From A air passes up around the 
posts 9 which are firmly attached to the diaphram stem 
7. Air also passes through the opening a in stem 7, 
and through the very small hole at b into chamber B. 
The lower end of stem 7, when in its normal position, 
makes a tight joint on the top of post 4 around the plug 
5, so that all air has to pass through b when charging up 
chamber B. After the signal equipment is charged to 



248 



NEW YORK AIR SIGNAL 



the standard pressure, a sudden reduction of pressure in 
the signal pipe by allowing air to escape at the car dis- 
charge valve will also reduce the pressure in chamber A. 
The air in B cannot equalize through b fast enough ; so 



TcstoNAk pire 




SIGNAL VALVE 1903 MODEL. 
pressure in B will raise diaphram 12, also raising disc 
valve 10 off its seat at c; air then passes from A to the 
whistle through e and gives a blast. When diaphram 12 
raises, the lower end of stem 7 at 11 raises off the post 4, 
air from chamber B can then pass up through 11 past 
plug 5, which is taper at its upper end, through passage 
a in stem 7 and equalize quickly with the air in chamber 
A. The diaphram at once drops to its normal position 
with stem 7 resting on post 4, seating valve 10 so no more 
air passes into the whistle. Air then feeds into A and B 
till the pressures are equalized with the signal pipe, when 
another reduction can be made at the car discharge valve 
and again operate the signal valve. 

The older type of New York Signal Valve is con- 
structed like the 1903 model, except that the opening a 
passing through diaphram stem 7 is very small, and air 



NEW YORK AIR SIGNAL 



249 



passes through a slowly when charging up B and out of 
chamber B much slower when the pressure in A is re- 
duced and diaphram 12 rises ; this causes diaphram to re- 
main up and hold valve 10 open longer than necessary. 

REDUCING VALVE. 




TO MAIN RESERVOIR 



The disc valve 10 and chamber A are the same in both 
types of signal valves; the bottom part, chamber B is 
much larger in the 1903 model than the older type, so 
there is a larger volume of air in chamber B of the 1903 
valve. 

The 1903 model charges up chamber B slowly; when 
diaphram 12 raises, air equalizes from B into A very 
quickly, thus giving a quick closing of disc valve 10. 

The reducing valve used with the New York signal 
apparatus is shown in section. Diaphram plate 6 is held 
down by a regulating spring 9 when there is less than 
standard pressure in A. This in turn holds supply valve 
5 off its seat so that main reservoir air entering at 4 can 
pass into A and through b into the signal pipe, charging 
it. A rubber diaphram 7 makes an air tight partition 
between the air in A and the outside air. The small 



250 REDUCING VALVE OPERATION 

holes v in the spring cap 3 are to allow any air that may 
leak past 7 to escape to the atmosphere. When the press- 
ure in A reaches the standard amount, usually 40 pounds, 
diaphram 7, stem 6 and nut 8 are raised by the air press- 
ure against the stiffness of spring 9. This allows spring 
10 to close supply valve 5 so that pressure in A will not 
raise any higher. When the opening of a car discharge 
valve or a leak in the signal pipe or its connections reduces 
the air pressure, spring 9 forces the diaphram down, opens 
the supply valve; this allows main reservoir air to feed 
into the signal pipe again. 

The object of a reducing valve is to maintain signal 
pipe pressure lower than that used in the operations of the 
brake, so that operating either the brake or signal will not 
interfere with the work of the other. The opening past 
the supply valve is made small so air will pass into the 
signal pipe slowly in order that a sufficient reduction can 
be made at the car discharge valve of any car to operate 
the signal valve. This could not be done if the reducing 
valve supplied air as fast as the car discharge valve took 
it out. 



OPERATING THE EQUIPMENT 

When making the initial or first service reduction in 
brake pipe pressure, to apply the brakes lightly on a train 
having both kinds of triple valves in operation, no change 
in the manner or amount of reduction is needed, as both 
Westinghouse and New York triples, if in good order, 
will apply their brakes alike. The initial reduction should 
be from 5 to 7 pounds, depending on the number of air 
brake cars operated; the length of the entire train and 
the speed at which it is running. A short train will not 
need so heavy an initial reduction as a longer train. 
There will not be so many triple valve feed ports to pass 
air from the auxiliaries to the brake pipe, which tends 
to prevent movement of the triple piston, and the volume 



OPERATING THE EQUIPMENT 251 

of brake pipe air is less in a short train than in a long 
one; so the reduction through the brake valve is made 
quicker, which moves the triples quicker. This in turn 
passes air into the brake cylinders faster, so the pistons 
move over the leakage grooves with less loss of air 
through the grooves. 

On a long train the first reduction may be 7 to 9 
pounds without giving serious shocks, unless the speed 
is very slow, in which case it is best to make a lighter 
reduction. A 5 pound initial reduction will give a cylinder 
pressure of less than 5 pounds on an 8-inch travel piston 
with the ordinary triple valves, which will not give any 
shock to a train. With K triples in the train a 5 pound 
reduction will give a higher cylinder pressure in their 
cylinders. If the train is moving fast, the initial reduction 
can be much heavier; especially in the case of a passenger 
train. It is advisable to apply the brakes with considerable 
force when at high speed, the retarding force of the shoes 
on the wheels is less in proportion than at slow speeds. 

With freight trains, at whatever speed, allow the slack 
to even up after shutting off steam before applying the 
brake, then apply it lightly in the case of slow speeds to 
bunch the train evenly and follow up with other reductions 
as may be necessary to control the train. Always wait at 
one reduction till the air has stopped flowing from the 
brake pipe exhaust of the brake valve and the triples have 
had a chance to act and the slack to even up before making 
another reduction. 

When operating the 1902 model New York brake valve, 
move the handle to first service position notch with a 
short train, and the air will at once begin to discharge 
from the brake pipe through an opening in the main 
slide valve, as the pressure reduces, the cut-off valve will 
close the opening, it will entirely close when the pressure is 
reduced the proper amount for that notch; it is not neces- 
sary to return the handle to lap position. Succeeding reduc- 
tions may then be made by moving the handle to the next 
service notches and allowing the valve to graduate the flow 



-252 OPERATING THE EQUIPMENT 

of brake pipe air and stop its discharge, or the handle can 
be stopped between the notches. When the last graduating 
notch is reached it is expected that a reduction of 20 to 23 
pounds will have been made in the brake pipe pressure. 
With a long train it may be necessary to go to the second 
or third notch in order to get a proper initial reduction on 
a long train. If quick action is desired at the triples, 
move the handle to the emergency position for the first 
reduction and leave it there till the train has stopped or 
the necessity for the quick stop has passed. This is a 
general rule for all brake valves and all triples in cases 
of emergency or danger which must be observed. 

With the older type of New York brake valve, the 
Vaughn-McKee valve, in order to have the valve cut off 
the discharge of brake pipe air automatically in a grad- 
uated application, the valve must have been placed in full 
release position long enough to discharge all air from the 
supplementary reservoir to allow brake pipe pressure to 
move the equalizing piston and the cut-off valve to their 
normal positions. It must then be moved to running 
position to recharge the supplementary reservoir from 
the brake pipe air till it equalizes, after which the piston 
would operate the cut-off valve in a graduated applica- 
tion. If the valve was only placed on running position 
to release brakes and moved to service application, the 
cut-off valve might be over the graduated reduction port 
so no air could pass out of brake pipe and it would be 
necessary to go farther back towards the emergency 
notch to discharge any brake pipe air. When operating 
the brake with this valve be sure to go to full release 
when releasing brakes, then stop on running position an 
instant if you expect the piston to operate the cut-off valve 
in a graduated service reduction. The 1902 model brake 
valve will graduate the flow of brake pipe air in a service 
application, as it automatically discharges and recharges 
the supplementary reservoir when at lap position or 
towards release. As the only proper position for the 
brake valve at the moment of releasing all brakes on any 



OPERATING THE EQUIPMENT 253 

kind of a train or engine is full release, this precaution 
can be observed. 

With a short train or lone engine the brake valve of 
whatever type can be moved from full release to running 
position in a few seconds and thus avoid overcharging the 
brake pipe in case there is a high main reservoir pressure. 

With a long brake pipe, leave the valve in full release 
about a half second for each car or until the black and red 
hands of the gauge have equalized at less than the standard 
brake pipe pressure, usually 70 pounds, then move to run- 
ning position and leave it there till the next application, 
unless the train is a very long one, when it is not unusual 
for a few of the brakes on the head end of the train to 
apply from overcharged auxiliaries, the head ones charging 
higher than those on the rear when main reservoir air is 
flowing rapidly into the brake pipe. If any set, they can be 
kicked off by going to full release for an instant. The 
New York brake valve has an excess valve to maintain a 
difference of pressure between the main reservoir and 
brake pipe so the instructions about carrying excess press- 
ure with the Westinghouse D-8 brake valve, found in the 
previous pages of this book, will apply to the New York 
brake valve. Questions 19 and 65 refer to this matter. 
Always use full release position to release brakes with 
any valve, and it is a vital point in quick recharging of 
auxiliaries, as when on a hill, to keep the valve in full 
release as long as possible. 

Many railroads have imperative, iron-clad rules about 
certain air brake work which are made to prevent careless 
or unskillful air brakemen from doing considerable dam- 
age. While only a very few of the men handling the brake 
may be in the class mentioned, yet the rule must be 
observed by the skillful as well as the careless ones. 
One of these rules is : "Do not release the brakes on a 
long train when running at a slow speed, but come to a 
full stop first" This speed is usually below eight miles 
an hour. This rule is made because the shocks to the 
train caused by the slack running in or out of the train 



254 OPERATING THE EQUIPMENT 

quicker than all the brakes can release, is usually certain 
to break the train in two or more parts. With the use 
of an additional engine and tender brake, either the 
Straight Air or the ET brake; retaining valves on engine 
and tender brakes or cocks so arranged as to hold the 
engine and tender brakes applied, or sufficient K triples 
at the head end, the train brake can be released at a slow 
speed without serious shocks. Retainers depend on tight 
piston packing and tight joints for their value. If the 
joints or packing leathers leak, retainers are useless for 
this purpose. This "iron-clad rule" applies as well to long 
passenger trains, when consisting of over twelve coaches, 
a release at slow speed without the use of some device 
on the engine to hold the slack is almost certain to break 
the train in two parts. The size of the main reservoir 
and amount of excess pressure have considerable to do 
with the ease and certainty of releasing all brakes quickly 
on a long train; large volume and high excess make the 
operation sure on a long train. You should remember 
that there is more difference in the reservoir and brake 
pipe pressures after a 20-pound reduction than after a 
5-pound reduction. This may explain the reason for 
stuck brakes on a long train after a light application. 
This matter is treated of in questions 12, 61 and 108. 
One prominent railroad handling long trains of air braked 
ore cars allows the release of a few brakes at a time when 
running at a slow speed, instead of coming to a full stop. 
After a full application or nearly so, when necessary to 
release a few of the brakes at a time and allow the train 
to keep moving during releasing, the brake valve is moved 
from lap to running position for an instant to raise the 
brake pipe pressure a very little, not over a pound, when 
a few brakes, usually those near the head end of the train 
will release. The next time the valve is placed in running 
position for an instant, brakes will release in various 
parts of the train; this operation can be repeated till the 
brake pipe pressure is raised about 5 pounds in all. 
Between each release allow the slack to even up. If this 



TRACING THE AIR 255 

work is skillfully done and the triples are in good order, 
very few brakes will remain applied after the 5-pound 
raise in pressure. Then with good stiff excess go to full 
release and quickly charge the brake pipe up its entire 
length to ensure that all triples are moved to release 
position. This process has a much different effect on a 
train at slow speed from releasing all triples with the same 
recharge of brake pipe. It also operates better on a train 
of ore cars which are either all loaded or all empty, than 
on an ordinary freight train having loads and empties 
mixed up in the train; for this reason it takes great skill 
to handle a freight train in this manner. A full release of 
all triples from one movement of the brake valve at slow 
speed, usually breaks the train in two; for that reason all 
roads condemn the practice. In releasing brakes an 
engineer should know the grades and how they affect the 
bunching or stretching of a train. 

One of the questions usually asked in an air brake 
examination is "trace the air through the air brake system; 
tell where it goes and how it operates the various parts 
of the equipment." Some air brake instructors ask this 
question at the beginning of their examination. As a 
complete answer to this question requires a good knowl- 
edge of the entire equipment, in this book it is left till 
the last. 

With the Westinghouse equipment, air from the atmos- 
phere enters at the inlet or receiving valves of the air 
pump, when the piston moves in the air cylinder, filling 
the space left by the piston. As the piston makes a stroke 
the air in the cylinder that is compressed passes by the 
discharge valves into the main reservoir and from there 
to the brake valve, where it is above the rotary valve. 
In full release position it passes through the direct supply 
port in rotary into the pocket in the rotary seat, around 
the partition, up into the large cavity in the lower side of 
the rotary, then into the brake pipe. At the same time 
it passes through the feed port in the rotary and the pre- 
liminary exhaust port into chamber D also through the 



256 TRACING THE AIR 

equalizing port into chamber D; main reservoir air goes 
to red hand of the duplex gage and pump governor and 
warning port to atmosphere. From chamber D, air goes 
to the black hand of gage. 

In running position air passes through the running 
position or feed port into the feed valve and, until the 
supply valve closes, on into the brake pipe. In this posi- 
tion air passes from the brake pipe up into the cavity in 
the rotary and then to chamber D through the equalizing 
port. With the D-8 or 1899 valve in running position air 
passes through feed port in rotary to the excess valve; 
by the excess valve into brake pipe. With D-8 valve brake 
pipe air goes to the governor, with the other valves, main 
reservoir air operates the governor. When the governor 
operates air flows past the diaphram valve in over the air 
piston and some air passes out the vent port. 

The air in chamber D flows into the brake valve reser- 
voir with all types of brake valve. Brake pipe air flows 
back until it reaches an angle cock or stop cock that is 
closed. It flows into every triple valve that is cut in and 
connected to the brake pipe, pressing against the bottom or 
brake pipe side of the triple piston. When this piston is 
in release position air flows through the feed groove 
around the triple piston into the auxiliary reservoir till 
the pressures are equalized. Air also passes up the pipe 
to the conductor's valve. When the pressures in the brake 
pipe and auxiliary have equalized at 70 pounds the brake 
is ready for an application; we will explain a service 
application first. 

Moving the handle of the rotary to service position 
first laps the port that admits main reservoir air to the 
brake pipe, closes the equalizing port between chamber D 
and the brake pipe and opens the preliminary exhaust port 
so chamber D air escapes to the atmosphere. This reduces 
chamber D pressure over the equalizing piston brake pipe 
pressure then raises this piston, which opens the brake pipe 
exhaust valve so brake pipe air flows to the atmosphere, 
reducing the pressure at each triple valve. The triple 



TRACING THE AIR 257 

piston moves towards the reducing pressure, closing the 
feed port, moving the graduating valve to open its port in 
the slide valve, the slide valve moves so the exhaust port 
is closed, next opening the air port to the brake cylinder 
so that auxiliary air flows into the brake cylinder and 
pushes out the brake piston which sets the brake. See 
question 37 for the Operation of the Distributing Valve. 

To release the brake, the brake valve is placed in full 
release position; main reservoir air passes into the brake 
pipe as already described. This moves the triple valves 
to release position, closing the air ports to the brake 
cylinder, opening the exhaust port so the air can flow 
from the cylinder to the atmosphere and opening the 
feed groove so brake pipe air can flow into the auxiliary. 
Air also flows into chamber D and brake valve reservoir. 

To release the ET brake the brake valve must be in 
running position, or the independent valve in release 
position. 

If a retaining valve is used, brake cylinder air, after 
leaving the exhaust port, passes through a pipe to the 
retainer, when this valve is in release position the air 
passes directly out. If the valve is in retaining position 
air pressure raises the valve and passes up into the case 
of the retainer and then out through the small opening 
in the case till the pressure drops to 15 pounds, when 
the valve seats and holds the air in the brake cylinder till 
the retainer is turned to release position. 

When making an emergency application of the brake 
the brake valve is placed in emergency position. Brake 
pipe air passes out very rapidly through the direct exhaust 
port at the same time chamber D air passes out at the 
preliminary exhaust port of the automatic brake valve. 
Air passes out of the brake pipe so rapidly that the triple 
valve cannot reduce auxiliary pressure as shown in service 
application, auxiliary air pressure moves the piston full 
stroke at once, auxiliary air passes by the removed corner 
of the slide valve through emergency port and on top of 
the emergency piston, pushing it down, this opens the 



258 TRACING THE AIR 

emergency valve and allows brake pipe air to pass into 
the brake cylinder, which sudden reduction of brake pipe 
pressure operates the next triple quick-action and so on 
throughout the whole train. At the same time auxiliary 
air passes through the tail port in the slide valve; also 
some air passes by the emergency piston into brake cylin- 
der till the pressures equalize. When the brake is set 
by opening the conductor's valve or by the train breaking 
in two, the operation is the same. 

In releasing brakes after an emergency application, the 
flow of air is the same as with a service application. We 
will add to this answer the signal equipment: The main 
reservoir air flows through the reducing valve till it 
reaches a pressure of 45 pounds; if the reducing valve is 
adjusted for that pressure. Air flows into the air signal 
pipe back to each car discharge valve. On the engine it 
passes from the signal pipe into the upper part of the 
signal valve, over the rubber diaphram into A, it also 
passes down to the lower part of the valve, up by the 
stem 10 slowly into chamber B until the pressure equalizes 
there with the signal pipe. When the whistle is to be 
operated from the train, the car discharge valve on the 
car is opened, air passes out of the signal pipe to the 
atmosphere. This reduces signal pipe pressure, when the 
reduction affects the pressure over the diaphram in the 
signal valve, the pressure under the diaphram not being 
reduced so quickly, air under it in B raises the diaphram 
and with it the valve 10, so that air flows out there to the 
whistle, giving a blast. When the valve 10 is raised, air 
in B flows past the flattened sides of this stem to the 
whistle; this quickly reduces the pressure in B and the 
diaphram drops, pushing valve 10 to its seat so no more 
air passes to the whistle. As soon as the brake pipe 
pressure falls below 45 pounds the reducing valve opens 
and begins to feed main reservoir air into the signal pipe 
slowly, as the opening through the valve is restricted or 
choked. If the air could pass into the signal pipe at the 
reducing valve as fast as it can pass out at a car discharge 



TRACING THE AIR 259 

valve, no reduction would be made in the signal pipe 
pressure. 

With the New York brake, the course of the air is a 
little different. Air flows from the atmosphere through 
the receiving valves into the air cylinders as the air 
pistons move up and down. The air in the high pressure 
air cylinder goes direct to the main reservoir when it is 
compressed. The air in the low pressure air cylinder, 
when compressed, passes into the high pressure air cylin- 
der and from there into the main reservoir, thence to the 
brake valve around and on top of the main slide valve; 
main reservoir air goes to the red hand of the gage and 
brake pipe air to the black hand. If a single governor 
is used it is operated by brake pipe air, if a duplex gover- 
nor one side by brake pipe air and the other by main 
reservoir air. When in release position it passes directly 
into the brake pipe and from the brake pipe into chamber 
D and the supplementary reservoir with the 1902 model 
valve. With the old style brake valve on release position 
the air in the supplementary reservoir and chamber D 
passes out through a small cavity in the slide valve to the 
atmosphere; this allows brake pipe pressure to move the 
equalizing piston to its normal position. On running 
position the main reservoir air passes by the excess valve 
and then into the brake pipe ; brake pipe air passes into the 
supplementary reservoir with the brake valve in this 
position. 

The brake pipe air passes back through the brake pipe 
to each triple valve that is cut in. At the triple valve the 
air passes through the port F in the vent valve piston and 
if the main piston is not already in release position, 
moves it there. Air then passes through the feed groove 
into the auxiliary until the pressure there has equalized 
with the brake pipe. With the Automatic Control Valve 
the course of air is explained at the operation of that 
valve. 

With a service application, the slide valve in the brake 



260 TRACING THE AIR 

valve is moved till the service port is open, brake pipe air 
then flows direct to the atmosphere until its pressure is 
reduced so the pressure of the air in the supplementary 
reservoir can move the piston, closing the cut-off valve 
and stopping the escape pf brake pipe air. 

This reduction of brake pipe pressure extends to each 
triple, auxiliary air pressure moves the triple piston, 
graduating valve and slide valve; first closing the feed 
groove, next the exhaust port and then opening the air 
port so air passes from the auxiliary to the cylinder. 
The air in the space G, between the main triple piston 
and the vent valve piston passes out through port F so 
the vent valve piston does not move in a service application. 

In an emergency application the slide valve in the 
brake valve is moved to emergency position. Brake pipe 
air passes rapidly out through the large ports in the slide 
valve, reducing brake pipe pressure so rapidly that the 
triple pistons make a quick stroke. As the air between 
the two pistons cannot pass through port F quickly enough, 
the vent valve piston moves with the main piston, unseats 
the vent valve; this allows brake pipe air to flow to the 
atmosphere. The air also pushes against the quick action 
piston, moving it over and with it opens the quick-action 
valve, which permits auxiliary air to flow through the 
passages into the cylinder, the check valve preventing this 
air from flowing back from the cylinder. Auxiliary air 
also flows into brake cylinder through the service port at 
the graduating valve. In releasing the brake the flow of 
air has already been described. 

The course of air through the signal equipment is the 
same as described with Westinghouse signal, except that 
air passes, from chamber A to chamber B through a small 
port b when charging up the signal valve, and out of B 
around the plug 4 to chamber A, when the signal valve 
operates. 



AIR BRAKE EXAMINATION QUESTIONS 

1. What are the essential parts of the automatic 
brake? What does each part do? 

2. Can you trace the course of the steam through the 
steam end of the air pump? Can you trace the course of 
the air through the pump? 

3. How should the pump be started and lubricated ? 

4. If the pump stops after working good for a time, 
where is the trouble likely to be? 

5. If it makes a quick stroke one way and a slow 
stroke the other, where is the trouble likely to be? 

6. What are the principal causes for a pump running 
hot? 

7. If the main reservoir is partly filled with water, 
which will it affect the most, setting or releasing the 
brake? Why? How often should it be drained? 

8. What might prevent the governor shutting off the 
steam and stopping the pump when maximum pressure is 
obtained? 

9. Where would you look for the trouble if governor 
stops the pump at much less than standard pressure? 

10. How do you adjust the governor with the ET 
brake ? 

11. Should you test the engine and tender equipment 
for leaks? 

12. How do you test for leaks in main reservoir and 
pipes from pump to brake valve? 

13. What other parts of the equipment gets air from 
the main reservoir besides the brake pipe? 

14. How do you test for a leak in brake pipe? In 
signal line? 

15. How do you locate a leak that lets off the brake? 

16. What pressure should you have before testing? 

17. What controls the excess pressure with the H-5 
and H-6 brake valve? With the F-6 valve? With the 
New York brake valve? 



262 EXAMINATION QUESTIONS 

18. How many kinds of engineer's brake valves have 
we in service on this road? 

19. Can you trace the air through each of them? 

20. Explain the principle of operation of the engineer's 
equalizing discharge brake valve. 

21. Describe its operation to apply the brake with 
service or emergency applications, and in releasing the 
brake. 

22. Why is excess pressure necessary? Do you need 
the most with a large main reservoir or a small one? 

23. Is more excess needed to release all the brakes on 
a long train than on a short one? 

24. How do you regulate the excess pressure with 
the H type brake valve? With the 1892 model or F-6 
valve ? 

25. Name the different positions of the brake valve. 
What extra position has the type H brake valve? 

26. What ports are open and what ports are closed 
in each position? 

27. Where does main reservoir pressure begin and 
end? 

28. Where does brake pipe pressure begin and end? 

29. Where does auxiliary pressure begin? 

30. . What is the equalizing port for? Is it open in 
all positions of the brake valve? 

31. Do leaks in the brake valve affect the operation 
of the brakes? Explain how. 

32. Do you consider a cut rotary valve or seat 
dangerous ? 

33. Will using the valve in emergency instead of 
service application cause this cutting any quicker? Why? 

34. What is the purpose of the small reservoir con- 
nected to the equalizing discharge valve? 

35. If the pipe leading from valve to small reservoir 
is broken off or leaking badly, what will you do? 

36. Where is the first air taken from in making a 
service stop? What port does it blow out of? 

37. Where does it come from? Where next? 



EXAMINATION QUESTIONS 263 

38. Does air ever blow out of brake pipe exhaust 
when releasing the brake? Why? 

39. Do you hear it when releasing brake on engine 
and tender only? Do you hear it with a train of over 
two cars? Do you hear it with the H type? 

40. If you are connected to more than two air cars 
and heard that blow, what would it indicate? 

41. How do you know that the brake valve is working 
properly? 

42. When applying the brakes can you tell about how 
many cars are connected with air to the brake valve by 
the amount of air escaping from the brake pipe exhaust? 
How do you make this test? 

43. How much do you reduce the brake pipe pressure 
from 70 pounds to set the brake as tight as possible? 

44. Why will this reduction do that? 

45. What is the difference between a reduction and 
an application? 

46. Does the length of travel of brake piston have 
anything to do with the pressure when brake is full set? 
How ? Explain fully. 

47. In making a service stop why should the brake 
valve not be moved past the service application position? 

48. Is this movement of the brake valve liable to kick 
off some of the head brakes? Why? 

49. What is the proper position to place brake valve 
in after releasing brakes if they are to be set again im- 
mediately? Why? Explain fully. 

50. What are the functions or uses of the triple valve? 

51. How many forms in use on this road ? Describe 
each form. 

52. Where does all the air come from that enters the 
brake cylinder through the plain triple when setting the 
brake ? 

53. Does all the air that goes into the brake cylinder 
of a quick-acting brake come from the auxiliary? 

54. Please explain the action of the quick-action triple 
when used in the emergency application. 



264 EXAMINATION QUESTIONS 

55. Can you get the emergency action after a service 
application? 

56. Does it take a sudden reduction of pressure right 
at the triple to work the quick-action valves or will a slow, 
heavy reduction do this? Why? 

57. If three or four cars at the head end of the train 
do not have quick-action triples working, can you get the 
emergency application behind these cars by a reduction 
at the brake valve? How many cars will the quick-actron 
"jump over?" 

58. What is the function of the graduating valve? 

59. Where is it located and how does it operate? 

60. If the graduating valve leaks on its seat, is the 
brake connected to that triple liable to release on a partial 
application? On a full application? Why is this? 

61. What is the function of the graduating stem and 
spring? 

62. If this spring is very weak or missing, how will 
it affect the work of the triple valve? 

63. How does the air get from the brake pipe into 
the auxiliary with the ordinary triple? With the K type? 

64. Why is this port so small? Could the brakes be 
set and released as certainly on a long train if this port 
was much larger? Would auxiliaries charge evenly? 

65. In what position of the triple valve is the port 
open ? 

66. How rapidly does an empty auxiliary charge up 
to 70 pounds with 70 in the brake pipe? 

67. How rapidly from 50 pounds up to 70 pounds? 

68. What regulates the time of charging each different 
sized auxiliary? 

69. If one auxiliary is charged up higher than another 
is the brake likely to creep on? Is it liable to take place 
when coupling up an air brake train? Explain why. 

70. Why is it dangerous to apply and release the brake 
repeatedly in making one station stop? 

71. Does this apply to a release and second applica- 



EXAMINATION QUESTIONS 265 

tion at a slow speed on slippery track? With a passenger 
train? Witlr a freight train? 

72. Do you understand that brake- cylinders have 
leakage grooves? Where are they located and how long 
are they? What are they for? 

73. Do you allow for them when setting the brake? 
How? 

74. As a rule how much reduction in brake pipe 
pressure is necessary to ensure that brake piston goes 
past the leakage groove? • 

75. Does a long train require more than a short train ? 
Why? 

76. What should be done after coupling to an air brake 
train before pulling out? 

77. .What pressure should you have in brake pipe and 
auxiliaries before testing the brake? 

78. How do you know when you have 70 pounds m 
the auxiliaries? 

79. What tests of air equipment are called for by our 
rules? Explain fully how these tests should be made. 

80. Are you required to test retaining valves? How 
is this done? 

81. If a brake is broken or disabled, how will you 
prevent it working on that car and let the brakes work on 
other cars? 

82. How do you cut out the brake on engine or 
tender ? 

83. Is it necessary to release the brake before cutting 
it out? 

84. How does the length of the piston travel affect the 
work of the brake? If it is too long? If it is too short? 

85. What is the proper piston travel? For passenger 
cars? For freight cars? For engine brakes? 

86. How is the slack taken up to secure this adjust- 
ment ? 

87. Should the triple be cut out before adjusting the 
levers to avoid injury to the workman in case brake 
goes on? 



266 EXAMINATION QUESTIONS 

88. At what travel should the driver brake piston be 
adjusted? How is the slack of a six-wheel brake taken 
up? 

89. What is necessary in order to have all the brakes 
work alike? 

90. When brakes go on suddenly and are not operated 
by the engineer, what should you do? To what causes 
would you assign this? 

91. If an air brake train breaks in two, how do you 
proceed to get train ready to go ahead again? How do 
you proceed in case of a bursted hose? How can you 
help trainmen to locate it? 

92. Would it be necessary in these cases to make a 
terminal test? 

93. If, after releasing train brake there is a steady 
leak from the exhaust port of the triple, what is the 
trouble ? 

94. What precautions must be observed in making a 
stop with a "part air" freight train? What with a long, 
"full air" train? 

95. In making a stop with a freight train, when would 
you let off the brakes to make a smooth stop? Why? 

96. When with a passenger train? Why? 

97. What is the pressure retaining valve, what is its 
use and how is it operated? Are there several kinds? 

98. How many pounds of air is it intended to close 
up on and hold in the brake cylinder? 

99. Does the brake release any slower till it gets 
down to this pressure, and how is it done? 

100. Can you get the emergency action of the brake 
with the pressure retainers holding 15 pounds? 

101. In descending a grade, how can you best keep a 
train under control? 

102. When two or more engines are coupled together, 
which engineer should do the braking? Why? 

103. How will you proceed to give the leading 
engineer complete control of the train? What should the 
second engineer do? 



EXAMINATION QUESTIONS 267 

104. If there is no cut-out cock on second engine 
under the brake valve, what should be done? 

105. How does the air signal equipment operate? 

106. What pressure should be carried in the signal 
line? How do you know you have this pressure? 

107. What causes the whistle to blow each time the 
brake is released? What makes it repeat the signal? 

108. Will a leak in the train signal pipe affect the 
working of the whistle? Explain. 

109. Explain the meaning of the signals given by one, 
two, three and four blasts of the signal whistle. 

110. What changes do you make in the engine equip- 
ment to carry 110 pounds brake pipe pressure instead of 
70, for the high speed brake?. For the type L triples? 

111. How many pounds brake pipe reduction in a 
service application will give a fully applied high speed 
brake ? 

112. Is it safe to use the emergency application of the 
high speed brake when running less than thirty miles an 
hour ? Why. 

113. Explain the action of the high speed reducing 
valve in service, and in emergency. 

114. What pressures should be in the brake cylinders 
on the engine and tender when the Straight Air brake is 
fully applied? 

115. How is this pressure regulated? 

116. Does long piston travel have any effect in reduc- 
ing this pressure? 

117. What valve closes the exhaust from the brake 
cylinder to the triple when the Straight Air is applied, 
and vice versa? Explain its operation. 

118. Is it good practice to use the automatic while 
the Straight Air is full set on the engine and tender brake? 
Why?. 

119. Should the Straight Air brake valve be left on 
lap position while operating the automatic? Why? 

120. How many air pipe connections at the Distribut- 



268 EXAMINATION QUESTIONS 

ing valve? Explain where the air comes . from and goes 
to at each of these connections,.;... 

121. How many pipe connections at .the H-5 brake 
valve? How many with the H-6? Where does the air 
come from and go to at each one? 

122. Explain the effect of leaks frbm each of these 
pipes and tell what you would do in each ease, if any of 
them break off. How do you locate these leaks? 

123. What is the duty of the equalizing piston and its 
slide valves in the Distributing valve, and what air press^ 
ures operate it? 

124. What is the duty of the application piston and 
its valves and what air pressures operate it? 

125. Why does the engine brake creep on when either 
brake valve is lapped? How will you, locate this defect? 

126. Will the engine brake stay applied if both brake 
valves are in running position? Why?: Will it creep on 
from leaks? 

127. Which brake valve is used to apply the auto- 
matic brake on train and engine? Which brake valve 
should be used to operate the engine brake only? 

128. What is the difference in the operation of the 
engine brake by the Independent brake valve and by the 
Straight Air brake valve? 

129. Does the safety valve on the Distributing valve 
control the application chamber pressure when the Inde- 
pendent brake valve is used?. Or in an automatic applica- 
tion only? Any difference between No. 5 and No. 6 ET? 

130. What valve regulates the brake cylinder pressure 
in a full application by the Independent brake valve? 

131. Explain the operation of the excess pressure side 
of the duplex pump governor. How do you set it? 

132. Is it necessary to move the New York brake 
valve to positive lap position at a brake pipe reduction, or 
should the valve be allowed to move itself to automatic 
lap? Why? 

133. Trace the course of the brake pipe air in the 
Westinghouse quick-action triple in release, service and 



EXAMINATION QUESTIONS 269 

emergency positions. Also do the same for the New 
York quick-action triple valve. 

134. Explain the retarded release of the K type triple. 

135. Explain the operation of the Westinghouse L 
type triple? 

136. Explain the operation of the New York Auto- 
matic Control brake. 



INDEX 

Air Pump — 8-inch 24-25-26 

Air Pump— 9^-inch . 7.7 26 to 30 

Air Pump — 1 1-inch 31 

Air Pump — Cross-Compound 37-38-39 

Air Pump— New York Duplex .192 to 199 

Accelerator valve — New York brake 222 

Air Signal — Westinghouse 146-157 

Air Signal— New York 7.247 to 250 

Auxiliary reservoir 22-47-107-136-189 

Automatic slack adjuster 174 to 176 

Air cylinder lubricator 31 

Automatic control— New York brake 225 to 231 

B-6 feed valve m ^ 

B-3 brake valve— New York brake .7 ... . 214 to 219 

Brakes leaking off 22-69-125-156-158 

Brakes creeping on 129 

Brakes sticking 7.7.7.7.7.'. 127-159-254 

Bursted hose 143 

Brake pipe pressure .7 .22-64 

Breaking in two 7 . . 144 

Brake leverage .21-177 to ' 185 

Charging auxiliaries 6-21-22-136 

Cutting out brakes 139-154 

Calculating air pressures 186 to 190 

Compensating valve— New York brake 241 

Definitions 23 

Distributing valve — No. 5 78 

Distributing valve — No. 6 92 

Defective air pump 33 to 36-198 

Defective brake valve 69-72-125-208 

Defective brake 128-130-154-158-159 

Defective governor 42-43 

Defective triple valve 17-113 to 115-154-239 

Defective brake pipe 133 

Defective piston packing 33-35-156 

Defective air signal 147-149-157 

Double heading 98-142 

E. T. equipment — No. 5 73 to 81 

E. T. equipment — No. 6 84 to 100 

Equalizing discharge brake valve 11-55 to 69 

Equalizing reservoir 22-56-69-189 

Excess pressure 52-53 

Emergency application 14 to 17-109-260 

Equalization 5-18-19-186-188 

Examination questions 261 to 269 

F-6 brake valve 54 to 56 



PAGE 

F-6 feed valve 58 

Full application 10-23-107 

Governor 41 to 46-200-202 

G-6 feed valve 60-61 

Graduating valve 7-106-113-233 

Graduated application 106-113-233 

H-5 brake valve 73 

H-6 brake valve 87 

Handling trains on grades 141 

High speed brake 163 to 171 

High pressure control 172 

Independent brake valve 77-90 

Inspection of brake equipment 21-48-134-135-153 

J triple valve — New York brake 243 

K type triple valve 116-118-251 

L type triple valve 119 to 124 

Leakage groove 22-106-137 

Leaks in brake pipe 50-129-158 

Leaks in brake cylinder 22-126-156 

Leaks in triple valve 125-154-251) 

Leaks in brake valve 69-72-125-208 

Leaky brake pipe check valve 125 

New York brake valve— 1902 model 251 

Operating the equipment 21-251 to 255 

Overcharging the brake pipe 19-127-130 

Plain triple valve 5-6-7-108-139-154 

Pressure retaining valve 144-152 

Position of brake valve 11-63 to 69-73-75-104-105 

Piston travel : 18-22-138-155 

Pressure on brake piston 18-105-107-138-187-188 

Quick action triple valve — Westinghouse. .15-18-108 to 114 

Quick action triple valve — New York 231 

Quick service triple valve 115-119 

Releasing brakes 9-131-254-257 

Reducing valve 62-148-211-249 

Straight air brake 101 to 104-209 

Slide valve feed valve 60 to 63 

Service application 7-23-107-206-233-251 

Safety valve 85-169-172 

Slack adjuster 174 to 176 

Testing for leaks 49-72-100-125-208-239 

Testing air signal 147-157 

Testing brake valve 69-72-125-208 

Testing the brakes 20-125-134-153 

Two-application stop 19-132 

Trainmen's questions 150 

Tracing the air 255 

Water raising system 160 to 162 



MITCHELL'S MODELS 



Are a series of cardboard models or 
charts, printed, colored and cut so clearly 
as to show the perfect and defective action 
of brake valves, triple valves, governors, 
etc. The relation existing between dif- 
ferent parts, passages and pieces of the 
apparatus is clearly shown and the function 
of each is explained in clear, simple lan- 
gauge so that after a little study the course 
of the air can be readily traced. 

No engineer, fireman, trainman, or per- 
son desiring to qualify for air brake exami- 
nation can afford to be without a set of 
Mitchell's Air-Brake Models. They in- 
sure your getting the necessary knowledge 
with least expenditure of time and labor. 

For further information write for free 
illustrated circular of Mitchell's Models, 
containing also valuable air-brake infor- 
mation. 



International Correspondence Schools 

Box 1221, Scranton. Pennsylvania 



GRAPHITE 



Dixon's Flake Graphite Lubricants 

They're the standard for economical, positive 
and efficient lubrication.:: 

Dixon's Graphite Pipe-Joint Compound 

For all threaded connections, insuring a tight fit 
and a joint that can be taken apart without damage. 

Dixon's Graphite Engine Front Finish 

Its brilliancy is unaffected by the elements. 
WRITE FOR LITERATURE ON THE ABOVE 

JOSEPH DIXON CRUCIBLE COMPANY 

* JERSEY CITY, N. J. 

THE 



Traveling Engineers Association 

At their annual meetings each year since 1893 
have had carefully prepared Committee Reports 
on a great number of practical questions concern- 
ing the operation of the locomotive and its var- 
ious attachments like the lubricator, injector, and 
air brake, as well as the proper handling of trains. 
The Committee Reports, together with the discus- 
sion thereon by the members of the Association, 
are printed for distribution to others who wish to 
inform themselves on these important topics. 
Copies of these Reports are on sale at the office 
of the secretary. Price 50 cents for paper bound; 
$1 for leather covers. Reports for the meetings 
previous to 1900 are all gone. Address, 

W. 0. THOMPSON, Secretary, 

N. Y. C. Car Shops 

EAST BUFFALO, N. Y. 



Chicago Locomotive Lubricator 

Class "C" 
3-Fceds with Solid Sight Feed Glasses 




To Operate 

Open steam valve full at boiler. Open valve 62 one 
turn. Open water valve 73 three turns. Note the feed 
glasses to see if filled with water. After the glasses are 
filled with water regulate feed with valve-31. 

The auxiliary oil cup 65, close pressure valve 62. 
See that valve 78 is closed. Open auxiliary drain valve 
88 to free cup of water. Open auxiliary filler plug 66 
and fill. After cup is filled, open feed valve 78 wide. 
This auxiliary cup can be operated with •team on lubri- 
cator and engine throttle open. 

Write us for full descriptive pamphlets. 

The Ohio Injector Co. 

1437 Monadnock Block, Chicago, 111. 



Star Brass Manufacturing Go. 



Air Brake (JwsMfr i 9 \ % m 
Inspectors' ^wm^^*i^ 

Gauges. ^^5§i 

The above illustration represents a very useful article 
that we have recently produced for the assistance of the 
Air Brake Inspector to instantly determine the pressure or 
test the signal apparatus by attaching to the hose couplings of 
the rear coach, as it will fit either the brake or signal coup- 
lings. These features obviate the necessity of the inspector 
consulting the air gauge in the cab, and the great advantage 
that this very useful instrument affords will readily be seen. 
The Test Gauge is only 2£ in. in diameter and weighs less than 
one pound. They are exclusively made by us and prices will 
be forwarded upon application. 

Also original and exclusive manufacturers of 

Westinghouse Duplex Air and Locomotive Gauges 

Fitted with our Patent Non-Corrosive Movement and 

Non-Setting corrugated Spring tubes 

Open and Muffled Locomotive Pop Safety Valves. 

Extra Heavy Water Gauges, Gauge Cocks, Lubricators, Etc. 

MAIN OFFICE AND WORKS 

104-14 E. Dedham St. Boston, Mass. 



BRANCHES 
421 Fulton Building, 70 Cortland St.. 

Pittsburgh, Pa. New YorK City 

404 St. James St.. 

Montreal. Canada 



Railroad Men's Catechism 

By Angus Sinclair Company 

Contains complete examination course for Engineers and 
Firemen. One of the most useful helps ever offered to Rail- 
way riien. Numerous illustrations, 200 pages,, flexible cloth. 
PRICE $1.00 



Locomotive Engine Running and 
Management 

By Angus Sinclair 

A book that has probably helped more enginemen than any 
other. Practical, reliable and brought up-to-date. Twenty- 
first edition ready. PRICE $2.00 



Twentieth Century Locomotives 

By Angus Sinclair Company 

It has 670 pages dealing with the designing, construction, re- 
pairing and operating of modern locomotives. Work shop 
operations, care and management of engines. Quick repairs 
on the road, shop tools, shop recipes, train resistance and 
power calculations, definitions and tables. Standard types of 
engines illustrated and described. Fully indexed. Most all 
round useful modern compendium of the locomotive. 
PRICE $2.00 



In addition to the above every railroad man should peruse 

Railway and Locomotive Engineering 

A high class illustrated monthly periodical universally ac- 
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improvements. Constantly describing and illustrating 

New Appliances New Methods New Features 

Sample Copies on Application 

TWO DOLLARS PER ANNUM 

Published by the 

Angus Sinclair Company 

114 Liberty Street New York 



BRAKEMAN'S 
AIR BRAKE AND SIGNAL COCK 

For Controlling From Rear of Trains When Backing 



THE methods of handling trains at terminals and passen- 
ger yards have entirely changed within a few years and 
it is now a universal practice that trains be backed into the 
station and from there to the yards. This makes it necessary 
to have them positively controlled from the rear end. It is 

also necessary to have a substi- 
tute for the engine bell, as a 
warning in passing into stations 
and yards. 

The cut shows a device which 
is designed to fulfill these re- 
quirements. It is a combined 
plug-cock and alarm whistle (A) 
attached by a short length of 
hose or pipe to the train "pipe" 
of the rear car. The whistle is 
blown by pressing the button (B) 
shown in the cut, which allows 
air to pass through the hollow 
handle of the cock to whistle, 
which is shown on the end of 
the handle, blowing the same 
and giving the necessary alarm. 
The air used for this pur* 
pose, on account of the 
design of the whistle valve, 
POSITIVELY does not 
affect the brake system. 
By moving the handle of the 
cock in either direction exhaust 
is made from the train pipe, 
through opening C, the brake 
set, and consequent positive con- 
trol of the train given. 
"The device is also valuable in switching of height trains, 
especially during the night or in thick weather, as the train 
by its use is under complete control from both ends. 




SHERBURNE & CO., 

Sole Manufactures 

53 Oliver Street, BOSTON, MASS., U. 



S. A. 



The American 
Automatic Slack Adjuster 




MANUFACTURED BY THE 

AMERICAN BRAKE COMPANY 

St Louis, Mo., U. S. A 




SAVE 



LIVES 

MONEY 

Collisions 



CHEAPER 

AND than 

More Reliable 



OIL 





Sellers Non-Lifting Injector of 1908 

Has all of the advantages and none of the 
disadvantages of the Lifting Injector 

RE-STARTING SELF ADJUSTING 

When the steam valve is opened, water is admitted 

automatically. When the steam valve is closed, 

lazy cock closes automatically. 

WM. SELLERS ft CO., Incp. Philadelphia, Pa. 



MAR 10 1910 



Deacidified using the Bookkeeper process. 
Neutralizing agent: Magnesium Oxide 
Treatment Date: April 2004 

PreservationTechnologies 

A WORLD LEADER IN PAPER PRESERVATION 

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